diff --git a/Cargo.lock b/Cargo.lock
index 722348c33..49871eeab 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -8,6 +8,7 @@ dependencies = [
  "daemonize 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "docopt 0.6.80 (registry+https://github.com/rust-lang/crates.io-index)",
  "env_logger 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ethabi 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "ethcore 1.5.0",
  "ethcore-dapps 1.5.0",
  "ethcore-devtools 1.5.0",
diff --git a/Cargo.toml b/Cargo.toml
index c3a44e1cc..b4020f198 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -48,6 +48,7 @@ ethcore-stratum = { path = "stratum" }
 ethcore-dapps = { path = "dapps", optional = true }
 clippy = { version = "0.0.103", optional = true}
 ethcore-light = { path = "ethcore/light" }
+ethabi = "0.2.2"
 
 [target.'cfg(windows)'.dependencies]
 winapi = "0.2"
diff --git a/ethcore/src/client/client.rs b/ethcore/src/client/client.rs
index 092819300..7fa714e8f 100644
--- a/ethcore/src/client/client.rs
+++ b/ethcore/src/client/client.rs
@@ -711,16 +711,6 @@ impl Client {
 		}
 	}
 
-	/// Look up the block number for the given block ID.
-	pub fn block_number(&self, id: BlockId) -> Option<BlockNumber> {
-		match id {
-			BlockId::Number(number) => Some(number),
-			BlockId::Hash(ref hash) => self.chain.read().block_number(hash),
-			BlockId::Earliest => Some(0),
-			BlockId::Latest | BlockId::Pending => Some(self.chain.read().best_block_number()),
-		}
-	}
-
 	/// Take a snapshot at the given block.
 	/// If the ID given is "latest", this will default to 1000 blocks behind.
 	pub fn take_snapshot<W: snapshot_io::SnapshotWriter + Send>(&self, writer: W, at: BlockId, p: &snapshot::Progress) -> Result<(), EthcoreError> {
@@ -946,6 +936,15 @@ impl BlockChainClient for Client {
 		Self::block_hash(&chain, id).and_then(|hash| chain.block_header_data(&hash))
 	}
 
+	fn block_number(&self, id: BlockId) -> Option<BlockNumber> {
+		match id {
+			BlockId::Number(number) => Some(number),
+			BlockId::Hash(ref hash) => self.chain.read().block_number(hash),
+			BlockId::Earliest => Some(0),
+			BlockId::Latest | BlockId::Pending => Some(self.chain.read().best_block_number()),
+		}
+	}
+
 	fn block_body(&self, id: BlockId) -> Option<Bytes> {
 		let chain = self.chain.read();
 		Self::block_hash(&chain, id).and_then(|hash| chain.block_body(&hash))
diff --git a/ethcore/src/client/test_client.rs b/ethcore/src/client/test_client.rs
index d2646b105..dd37a3c02 100644
--- a/ethcore/src/client/test_client.rs
+++ b/ethcore/src/client/test_client.rs
@@ -473,6 +473,10 @@ impl BlockChainClient for TestBlockChainClient {
 		self.block_hash(id).and_then(|hash| self.blocks.read().get(&hash).map(|r| Rlp::new(r).at(0).as_raw().to_vec()))
 	}
 
+	fn block_number(&self, _id: BlockId) -> Option<BlockNumber> {
+		unimplemented!()
+	}
+
 	fn block_body(&self, id: BlockId) -> Option<Bytes> {
 		self.block_hash(id).and_then(|hash| self.blocks.read().get(&hash).map(|r| {
 			let mut stream = RlpStream::new_list(2);
diff --git a/ethcore/src/client/traits.rs b/ethcore/src/client/traits.rs
index a6956461e..8f5d4c77a 100644
--- a/ethcore/src/client/traits.rs
+++ b/ethcore/src/client/traits.rs
@@ -52,6 +52,9 @@ pub trait BlockChainClient : Sync + Send {
 	/// Get raw block header data by block id.
 	fn block_header(&self, id: BlockId) -> Option<Bytes>;
 
+	/// Look up the block number for the given block ID.
+	fn block_number(&self, id: BlockId) -> Option<BlockNumber>;
+	
 	/// Get raw block body data by block id.
 	/// Block body is an RLP list of two items: uncles and transactions.
 	fn block_body(&self, id: BlockId) -> Option<Bytes>;
diff --git a/parity/blockchain.rs b/parity/blockchain.rs
index d62f2b9bb..ffbe15068 100644
--- a/parity/blockchain.rs
+++ b/parity/blockchain.rs
@@ -178,7 +178,6 @@ fn execute_import(cmd: ImportBlockchain) -> Result<String, String> {
 	// prepare client config
 	let mut client_config = to_client_config(
 		&cmd.cache_config, 
-		Default::default(),
 		Mode::Active, 
 		tracing, 
 		fat_db, 
@@ -345,7 +344,7 @@ fn start_client(
 	try!(execute_upgrades(&db_dirs, algorithm, compaction.compaction_profile(db_dirs.fork_path().as_path())));
 
 	// prepare client config
-	let client_config = to_client_config(&cache_config, Default::default(), Mode::Active, tracing, fat_db, compaction, wal, VMType::default(), "".into(), algorithm, pruning_history, true);
+	let client_config = to_client_config(&cache_config, Mode::Active, tracing, fat_db, compaction, wal, VMType::default(), "".into(), algorithm, pruning_history, true);
 
 	let service = try!(ClientService::start(
 		client_config,
diff --git a/parity/configuration.rs b/parity/configuration.rs
index ca3189827..c9358cd35 100644
--- a/parity/configuration.rs
+++ b/parity/configuration.rs
@@ -23,7 +23,7 @@ use cli::{Args, ArgsError};
 use util::{Hashable, U256, Uint, Bytes, version_data, Secret, Address};
 use util::log::Colour;
 use ethsync::{NetworkConfiguration, is_valid_node_url, AllowIP};
-use ethcore::client::{VMType, UpdatePolicy, UpdateFilter};
+use ethcore::client::{VMType};
 use ethcore::miner::{MinerOptions, Banning};
 use ethcore::verification::queue::VerifierSettings;
 
@@ -37,6 +37,7 @@ use ethcore_logger::Config as LogConfig;
 use dir::Directories;
 use dapps::Configuration as DappsConfiguration;
 use signer::{Configuration as SignerConfiguration};
+use updater::{UpdatePolicy, UpdateFilter};
 use run::RunCmd;
 use blockchain::{BlockchainCmd, ImportBlockchain, ExportBlockchain, ExportState, DataFormat};
 use presale::ImportWallet;
diff --git a/parity/helpers.rs b/parity/helpers.rs
index 25acfcc55..60a04bc45 100644
--- a/parity/helpers.rs
+++ b/parity/helpers.rs
@@ -20,7 +20,7 @@ use std::time::Duration;
 use std::fs::File;
 use util::{clean_0x, U256, Uint, Address, path, CompactionProfile};
 use util::journaldb::Algorithm;
-use ethcore::client::{UpdatePolicy, Mode, BlockId, VMType, DatabaseCompactionProfile, ClientConfig, VerifierType};
+use ethcore::client::{Mode, BlockId, VMType, DatabaseCompactionProfile, ClientConfig, VerifierType};
 use ethcore::miner::{PendingSet, GasLimit, PrioritizationStrategy};
 use cache::CacheConfig;
 use dir::DatabaseDirectories;
diff --git a/parity/informant.rs b/parity/informant.rs
index 1f3f3862a..31f5c3e81 100644
--- a/parity/informant.rs
+++ b/parity/informant.rs
@@ -19,12 +19,14 @@ use self::ansi_term::Colour::{White, Yellow, Green, Cyan, Blue};
 use self::ansi_term::Style;
 
 use std::sync::{Arc};
-use std::sync::atomic::{AtomicUsize, Ordering as AtomicOrdering};
+use std::sync::atomic::{AtomicUsize, AtomicBool, Ordering as AtomicOrdering};
 use std::time::{Instant, Duration};
+use io::{TimerToken, IoContext, IoHandler};
 use isatty::{stdout_isatty};
 use ethsync::{SyncProvider, ManageNetwork};
 use util::{Uint, RwLock, Mutex, H256, Colour};
 use ethcore::client::*;
+use ethcore::service::ClientIoMessage;
 use ethcore::views::BlockView;
 use ethcore::snapshot::service::Service as SnapshotService;
 use ethcore::snapshot::{RestorationStatus, SnapshotService as SS};
@@ -44,6 +46,7 @@ pub struct Informant {
 	last_import: Mutex<Instant>,
 	skipped: AtomicUsize,
 	skipped_txs: AtomicUsize,
+	in_shutdown: AtomicBool,
 }
 
 /// Format byte counts to standard denominations.
@@ -82,9 +85,14 @@ impl Informant {
 			last_import: Mutex::new(Instant::now()),
 			skipped: AtomicUsize::new(0),
 			skipped_txs: AtomicUsize::new(0),
+			in_shutdown: AtomicBool::new(false),
 		}
 	}
 
+	/// Signal that we're shutting down; no more output necessary.
+	pub fn shutdown(&self) {
+		self.in_shutdown.store(true, ::std::sync::atomic::Ordering::SeqCst);
+	}
 
 	#[cfg_attr(feature="dev", allow(match_bool))]
 	pub fn tick(&self) {
@@ -222,14 +230,16 @@ impl ChainNotify for Informant {
 	}
 }
 
+const INFO_TIMER: TimerToken = 0;
+
 impl IoHandler<ClientIoMessage> for Informant {
 	fn initialize(&self, io: &IoContext<ClientIoMessage>) {
 		io.register_timer(INFO_TIMER, 5000).expect("Error registering timer");
 	}
 
 	fn timeout(&self, _io: &IoContext<ClientIoMessage>, timer: TimerToken) {
-		if timer == INFO_TIMER && !self.shutdown.load(Ordering::SeqCst) {
-			self.info.tick();
+		if timer == INFO_TIMER && !self.in_shutdown.load(AtomicOrdering::SeqCst) {
+			self.tick();
 		}
 	}
 }
diff --git a/parity/main.rs b/parity/main.rs
index cf5ba7391..7d5426eb9 100644
--- a/parity/main.rs
+++ b/parity/main.rs
@@ -25,6 +25,7 @@
 extern crate docopt;
 extern crate num_cpus;
 extern crate rustc_serialize;
+extern crate ethabi;
 extern crate ethcore_devtools as devtools;
 extern crate ethcore;
 extern crate ethsync;
@@ -87,7 +88,6 @@ mod upgrade;
 mod rpc;
 mod dapps;
 mod informant;
-mod io_handler;
 mod cli;
 mod configuration;
 mod migration;
@@ -111,7 +111,6 @@ mod boot;
 mod user_defaults;
 mod updater;
 mod operations;
-mod fetch;
 
 #[cfg(feature="stratum")]
 mod stratum;
@@ -254,12 +253,12 @@ fn main() {
 	// if argv[0] == "parity" and this executable != ~/.parity-updates/parity, run that instead.
 	let force_direct = std::env::args().any(|arg| arg == "--force-direct");
 	let exe = std::env::current_exe().ok();
-	let development = exe.and_then(|p| p.parent().and_then(|p| p.parent()).and_then(|p| p.file_name()).map(|n| n == "target")).unwrap_or(false);
-	let same_name = exe.and_then(|p| p.file_stem().map_or(false, |s| s == "parity"));
+	let development = exe.as_ref().and_then(|p| p.parent().and_then(|p| p.parent()).and_then(|p| p.file_name()).map(|n| n == "target")).unwrap_or(false);
+	let same_name = exe.as_ref().and_then(|p| p.file_stem().map(|s| s == "parity")).unwrap_or(false);
 	let have_update = updates_latest().exists();
-	let is_non_updated_current = exe.map_or(false, p.canonicalize() != updates_latest().canonicalize());
-	trace_main!("Starting up {} (force-direct: {}, development: {}, have-update: {}, non-updated-current: {})", std::env::current_exe().map(|x| format!("{}", x.display())).unwrap_or("<unknown>".to_owned()), force_direct, development, have_update, is_non_updated_current);
-	if !force_direct && ! development && have_update && is_non_updated_current {
+	let is_non_updated_current = exe.map_or(false, |p| p.canonicalize().ok() != updates_latest().canonicalize().ok());
+	trace_main!("Starting up {} (force-direct: {}, development: {}, same-name: {}, have-update: {}, non-updated-current: {})", std::env::current_exe().map(|x| format!("{}", x.display())).unwrap_or("<unknown>".to_owned()), force_direct, development, same_name, have_update, is_non_updated_current);
+	if !force_direct && !development && same_name && have_update && is_non_updated_current {
 		// looks like we're not running ~/.parity-updates/parity when the user is expecting otherwise.
 		// Everything run inside a loop, so we'll be able to restart from the child into a new version seamlessly. 
 		loop {
diff --git a/parity/run.rs b/parity/run.rs
index 2a7ecf12e..7d7fbff0c 100644
--- a/parity/run.rs
+++ b/parity/run.rs
@@ -14,16 +14,16 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
-use std::sync::{Arc, Mutex, Condvar};
+use std::sync::Arc;
 use std::net::{TcpListener};
 use ctrlc::CtrlC;
 use fdlimit::raise_fd_limit;
 use ethcore_rpc::{NetworkSettings, is_major_importing};
 use ethsync::NetworkConfiguration;
-use util::{Colour, version, RotatingLogger};
+use util::{Colour, version, RotatingLogger, Mutex, Condvar};
 use io::{MayPanic, ForwardPanic, PanicHandler};
 use ethcore_logger::{Config as LogConfig};
-use ethcore::client::{Mode, UpdatePolicy, Updater, DatabaseCompactionProfile, VMType, ChainNotify, BlockChainClient};
+use ethcore::client::{Mode, DatabaseCompactionProfile, VMType, BlockChainClient};
 use ethcore::service::ClientService;
 use ethcore::account_provider::AccountProvider;
 use ethcore::miner::{Miner, MinerService, ExternalMiner, MinerOptions};
@@ -31,7 +31,7 @@ use ethcore::snapshot;
 use ethcore::verification::queue::VerifierSettings;
 use ethsync::SyncConfig;
 use informant::Informant;
-use updater::Updater;
+use updater::{UpdatePolicy, Updater};
 
 use rpc::{HttpServer, IpcServer, HttpConfiguration, IpcConfiguration};
 use signer::SignerServer;
@@ -312,10 +312,8 @@ pub fn execute(cmd: RunCmd, logger: Arc<RotatingLogger>) -> Result<bool, String>
 	}
 
 	// the updater service
-	let updater = Updater::new(service.client(), update_policy);
-	if let Some(ref u) = updater {
-		service.add_notify(u.clone());
-	}
+	let updater = Updater::new(Arc::downgrade(&(service.client() as Arc<BlockChainClient>)), update_policy);
+	service.add_notify(updater.clone());
 
 	// set up dependencies for rpc servers
 	let signer_path = cmd.signer_conf.signer_path.clone();
@@ -422,9 +420,9 @@ pub fn execute(cmd: RunCmd, logger: Arc<RotatingLogger>) -> Result<bool, String>
 	info!("Finishing work, please wait...");
 
 	// to make sure timer does not spawn requests while shutdown is in progress
-	io_handler.shutdown.store(true, ::std::sync::atomic::Ordering::SeqCst);
+	informant.shutdown();
 	// just Arc is dropping here, to allow other reference release in its default time
-	drop(io_handler);
+	drop(informant);
 
 	// hypervisor should be shutdown first while everything still works and can be
 	// terminated gracefully
@@ -474,7 +472,7 @@ fn wait_for_exit(
 	_ipc_server: Option<IpcServer>,
 	_dapps_server: Option<WebappServer>,
 	_signer_server: Option<SignerServer>,
-	updater: Option<Arc<Updater>>
+	updater: Arc<Updater>
 ) -> bool {
 	let exit = Arc::new((Mutex::new(false), Condvar::new()));
 
@@ -487,12 +485,11 @@ fn wait_for_exit(
 	panic_handler.on_panic(move |_reason| { e.1.notify_all(); });
 
 	// Handle updater wanting to restart us
-	if let Some(ref u) = updater {
-		let e = exit.clone();
-		u.set_exit_handler(move || { e.0.lock() = true; e.1.notify_all(); });
-	}
+	let e = exit.clone();
+	updater.set_exit_handler(move || { *e.0.lock() = true; e.1.notify_all(); });
 
 	// Wait for signal
-	let _ = exit.1.wait(exit.0.lock().unwrap());
-	*exit.0.lock()
+	let mut l = exit.0.lock();
+	let _ = exit.1.wait(&mut l);
+	*l
 }
diff --git a/parity/snapshot.rs b/parity/snapshot.rs
index d74adc1b4..804047596 100644
--- a/parity/snapshot.rs
+++ b/parity/snapshot.rs
@@ -170,7 +170,7 @@ impl SnapshotCommand {
 		try!(execute_upgrades(&db_dirs, algorithm, self.compaction.compaction_profile(db_dirs.fork_path().as_path())));
 
 		// prepare client config
-		let client_config = to_client_config(&self.cache_config, Default::default(), Mode::Active, tracing, fat_db, self.compaction, self.wal, VMType::default(), "".into(), algorithm, self.pruning_history, true);
+		let client_config = to_client_config(&self.cache_config, Mode::Active, tracing, fat_db, self.compaction, self.wal, VMType::default(), "".into(), algorithm, self.pruning_history, true);
 
 		let service = try!(ClientService::start(
 			client_config,
diff --git a/parity/updater.rs b/parity/updater.rs
index 42def8b5a..85ceb7493 100644
--- a/parity/updater.rs
+++ b/parity/updater.rs
@@ -14,15 +14,14 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
-use std::sync::{Weak};
+use std::sync::{Arc, Weak};
 use std::{io, os, fs, env};
 use std::path::{Path, PathBuf};
 use util::misc::{VersionInfo, ReleaseTrack/*, platform*/};
-use util::{Address, H160, H256, FixedHash, Mutex};
+use util::{Address, H160, H256, FixedHash, Mutex, Bytes};
 use super::operations::Operations;
-use ethcore::client::{Client, BlockId};
-use fetch::HashFetch;
-use fetch;
+use ethcore::client::{BlockId, BlockChainClient, ChainNotify};
+use hash_fetch::{self as fetch, HashFetch};
 
 /// Filter for releases.
 #[derive(Debug, Eq, PartialEq, Clone)]
@@ -94,11 +93,11 @@ struct UpdaterState {
 pub struct Updater {
 	// Useful environmental stuff.
 	update_policy: UpdatePolicy,
-	weak_self: Weak<Updater>,
-	client: Weak<Client>,
+	weak_self: Mutex<Weak<Updater>>,
+	client: Weak<BlockChainClient>,
 	fetcher: Option<fetch::Client>,
 	operations: Mutex<Option<Operations>>,
-	exit_handler: Mutex<Option<Fn()>>,
+	exit_handler: Mutex<Option<Box<Fn() + 'static + Send>>>,
 
 	// Our version info (static)
 	this: VersionInfo,
@@ -128,7 +127,7 @@ impl Updater {
 	pub fn new(client: Weak<BlockChainClient>, update_policy: UpdatePolicy) -> Arc<Self> {
 		let mut u = Updater {
 			update_policy: update_policy,
-			weak_self: Default::default(),
+			weak_self: Mutex::new(Default::default()),
 			client: client.clone(),
 			fetcher: None,
 			operations: Mutex::new(None),
@@ -142,9 +141,9 @@ impl Updater {
 			u.this.track = ReleaseTrack::Nightly;
 		}
 
-		let r = Arc::new(u);
-		r.as_mut().weak_self = Arc::downgrade(&r);
-		r.as_mut().fetcher = Some(fetch::Client::new(r));
+		let mut r = Arc::new(u);
+		Arc::get_mut(&mut r).expect("arc created on previous line; qed").fetcher = Some(fetch::Client::new(r.clone()));
+		*r.weak_self.lock() = Arc::downgrade(&r);
 		r
 	}
 
@@ -167,9 +166,9 @@ impl Updater {
 
 	/// Actually upgrades the client. Assumes that the binary has been downloaded.
 	/// @returns `true` on success.
-	pub fn execute_upgrade(&mut self) -> bool {
+	pub fn execute_upgrade(&self) -> bool {
 		(|| -> Result<bool, String> {
-			let s = state.lock();
+			let mut s = self.state.lock();
 			if let Some(r) = s.ready.take() {
 				let p = Self::update_file_path(&r.version);
 				let n = Self::updates_latest();
@@ -178,7 +177,7 @@ impl Updater {
 					Ok(_) => {
 						info!("Completed upgrade to {}", &r.version);
 						s.installed = Some(r);
-						if let Some(ref h) = self.exit_handler().lock() {
+						if let Some(ref h) = *self.exit_handler.lock() {
 							(*h)();
 						}
 						Ok(true)
@@ -195,14 +194,6 @@ impl Updater {
 		})().unwrap_or_else(|e| { warn!("{}", e); false })
 	}
 
-	/// Returns true iff the current version is capable of forming consensus.
-	pub fn is_consensus_capable(&self) -> bool {
-/*		if let Some(ref latest) = self.latest {
-			
-
-*/		unimplemented!()
-	}
-
 	/// Our version info.
 	pub fn version_info(&self) -> &VersionInfo { &self.this }
 
@@ -210,13 +201,13 @@ impl Updater {
 	pub fn info(&self) -> Option<OperationsInfo> { self.state.lock().latest.clone() }
 
 	/// Set a closure to call when we want to restart the client
-	pub fn set_exit_handler(&self, f: Fn()) {
-		*self.exit_handler.lock() = f; 
+	pub fn set_exit_handler<F>(&self, f: F) where F: Fn() + 'static + Send {
+		*self.exit_handler.lock() = Some(Box::new(f)); 
 	}
 
-	fn collect_release_info(&self, release_id: &H256) -> Result<ReleaseInfo, String> {
-		let (fork, track, semver, is_critical) = self.operations.release(CLIENT_ID, release_id)?;
-		let latest_binary = self.operations.checksum(CLIENT_ID, release_id, &platform())?;
+	fn collect_release_info(operations: &Operations, release_id: &H256) -> Result<ReleaseInfo, String> {
+		let (fork, track, semver, is_critical) = operations.release(CLIENT_ID, release_id)?;
+		let latest_binary = operations.checksum(CLIENT_ID, release_id, &platform())?;
 		Ok(ReleaseInfo {
 			version: VersionInfo::from_raw(semver, track, release_id.clone().into()),
 			is_critical: is_critical,
@@ -226,32 +217,36 @@ impl Updater {
 	}
 
 	fn collect_latest(&self) -> Result<OperationsInfo, String> {
-		let this_fork = u.operations.release(CLIENT_ID, &u.this.hash.into()).ok()
-			.and_then(|(fork, track, _, _)| if track > 0 {Some(fork as u64)} else {None});
+		if let Some(ref operations) = *self.operations.lock() {
+			let this_fork = operations.release(CLIENT_ID, &self.this.hash.into()).ok()
+				.and_then(|(fork, track, _, _)| if track > 0 {Some(fork as u64)} else {None});
 
-		if self.this.track == ReleaseTrack::Unknown {
-			return Err(format!("Current executable ({}) is unreleased.", H160::from(self.this.hash)));
+			if self.this.track == ReleaseTrack::Unknown {
+				return Err(format!("Current executable ({}) is unreleased.", H160::from(self.this.hash)));
+			}
+
+			let latest_in_track = operations.latest_in_track(CLIENT_ID, self.this.track.into())?;
+			let in_track = Self::collect_release_info(operations, &latest_in_track)?;
+			let mut in_minor = Some(in_track.clone());
+			const PROOF: &'static str = "in_minor initialised and assigned with Some; loop breaks if None assigned; qed";
+			while in_minor.as_ref().expect(PROOF).version.track != self.this.track {
+				let track = match in_minor.as_ref().expect(PROOF).version.track {
+					ReleaseTrack::Beta => ReleaseTrack::Stable,
+					ReleaseTrack::Nightly => ReleaseTrack::Beta,
+					_ => { in_minor = None; break; }
+				};
+				in_minor = Some(Self::collect_release_info(operations, &operations.latest_in_track(CLIENT_ID, track.into())?)?);
+			}
+
+			Ok(OperationsInfo {
+				fork: operations.latest_fork()? as u64,
+				this_fork: this_fork,
+				track: in_track,
+				minor: in_minor,
+			})
+		} else {
+			Err("Operations not available".into())
 		}
-
-		let latest_in_track = self.operations.latest_in_track(CLIENT_ID, self.this.track.into())?;
-		let in_track = self.collect_release_info(&latest_in_track)?;
-		let mut in_minor = Some(in_track.clone());
-		const PROOF: &'static str = "in_minor initialised and assigned with Some; loop breaks if None assigned; qed";
-		while in_minor.as_ref().expect(PROOF).version.track != self.this.track {
-			let track = match in_minor.as_ref().expect(PROOF).version.track {
-				ReleaseTrack::Beta => ReleaseTrack::Stable,
-				ReleaseTrack::Nightly => ReleaseTrack::Beta,
-				_ => { in_minor = None; break; }
-			};
-			in_minor = Some(self.collect_release_info(&self.operations.latest_in_track(CLIENT_ID, track.into())?)?);
-		}
-
-		Ok(OperationsInfo {
-			fork: self.operations.latest_fork()? as u64,
-			this_fork: this_fork,
-			track: in_track,
-			minor: in_minor,
-		})
 	}
 
 	fn update_file_path(v: &VersionInfo) -> PathBuf {
@@ -268,10 +263,10 @@ impl Updater {
 		dest
 	}
 
-	fn fetch_done(&mut self, result: Result<PathBuf, fetch::Error>) {
+	fn fetch_done(&self, result: Result<PathBuf, fetch::Error>) {
 		(|| -> Result<(), String> {
 			let auto = {
-				let mut s = state.lock();
+				let mut s = self.state.lock();
 				let fetched = s.fetching.take().unwrap();
 				let b = result.map_err(|e| format!("Unable to fetch update ({}): {:?}", fetched.version, e))?;
 				info!("Fetched latest version ({}) OK to {}", fetched.version, b.display());
@@ -288,17 +283,18 @@ impl Updater {
 				auto
 			};
 			if auto {
+				// will lock self.state, so ensure it's outside of previous block.
 				self.execute_upgrade();
 			}
 			Ok(())
 		})().unwrap_or_else(|e| warn!("{}", e));
 	}
 
-	fn poll(&mut self) {
+	fn poll(&self) {
 		info!(target: "updater", "Current release is {}", self.this);
 
-		if *self.operations.lock().is_none() {
-			if let Some(ops_addr) = client.upgrade().registry_address("operations") {
+		if self.operations.lock().is_none() {
+			if let Some(ops_addr) = self.client.upgrade().and_then(|c| c.registry_address("operations".into())) {
 				trace!(target: "client", "Found operations at {}", ops_addr);
 				let client = self.client.clone();
 				*self.operations.lock() = Some(Operations::new(ops_addr, move |a, d| client.upgrade().ok_or("No client!".into()).and_then(|c| c.call_contract(a, d))));
@@ -308,8 +304,6 @@ impl Updater {
 			}
 		}
 
-		u.latest = u.collect_latest().ok();
-
 		let current_number = self.client.upgrade().map_or(0, |c| c.block_number(BlockId::Latest).unwrap_or(0));
 
 		let latest = self.collect_latest().ok();
@@ -329,23 +323,23 @@ impl Updater {
 			let already_have_latest = s.installed.as_ref().or(s.ready.as_ref()).map_or(false, |t| *t == latest.track);
 			if self.update_policy.enable_downloading && !running_latest && !already_have_latest {
 				if let Some(b) = latest.track.binary {
-					if fetching.is_none() {
+					if s.fetching.is_none() {
 						info!("Attempting to get parity binary {}", b);
 						s.fetching = Some(latest.track.clone());
-						let weak_self = self.weak_self.clone();
-						let f = move |r: Result<PathBuf, fetch::Error>| if let Some(this) = weak_self.upgrade().as_mut() { this.fetch_done(r) }};
-						fetcher.fetch(b, Box::new(f)).ok();
+						let weak_self = self.weak_self.lock().clone();
+						let f = move |r: Result<PathBuf, fetch::Error>| if let Some(this) = weak_self.upgrade() { this.fetch_done(r) };
+						self.fetcher.as_ref().expect("Created on `new`; qed").fetch(b, Box::new(f)).ok();
 					}
 				}
 			}
-			info!(target: "updater", "Fork: this/current/latest/latest-known: {}/#{}/#{}/#{}", match s.latest.this_fork { Some(f) => format!("#{}", f), None => "unknown".into(), }, current_number, s.latest.track.fork, s.latest.fork);
+			info!(target: "updater", "Fork: this/current/latest/latest-known: {}/#{}/#{}/#{}", match latest.this_fork { Some(f) => format!("#{}", f), None => "unknown".into(), }, current_number, latest.track.fork, latest.fork);
 		}
 		(*self.state.lock()).latest = latest;
 	}
 }
 
 impl ChainNotify for Updater {
-	fn new_blocks(&self, _imported: Vec<H256>, _invalid: Vec<H256>, _enacted: Vec<H256>, _retracted: Vec<H256>, _sealed: Vec<H256>, duration: u64) {
+	fn new_blocks(&self, _imported: Vec<H256>, _invalid: Vec<H256>, _enacted: Vec<H256>, _retracted: Vec<H256>, _sealed: Vec<H256>, _duration: u64) {
 		// TODO: something like this
 //		if !self.client.upgrade().map_or(true, |c| c.is_major_syncing()) {
 			self.poll();