diff --git a/Cargo.toml b/Cargo.toml
index 872e1e675..eef261317 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -22,6 +22,7 @@ ethash = { path = "ethash" }
 num_cpus = "0.2"
 clippy = "0.0.37"
 crossbeam = "0.1.5"
+lazy_static = "0.1"
 
 [features]
 jit = ["evmjit"]
diff --git a/res/ethereum/frontier.json b/res/ethereum/frontier.json
index 9cb456ce8..43be680d2 100644
--- a/res/ethereum/frontier.json
+++ b/res/ethereum/frontier.json
@@ -3,7 +3,7 @@
 	"engineName": "Ethash",
 	"params": {
 		"accountStartNonce": "0x00",
-		"frontierCompatibilityModeLimit": "0xDBBA0",
+		"frontierCompatibilityModeLimit": "0xdbba0",
 		"maximumExtraDataSize": "0x20",
 		"tieBreakingGas": false,
 		"minGasLimit": "0x1388",
diff --git a/res/ethereum/homestead_test.json b/res/ethereum/homestead_test.json
index b11ef9740..1fb5dff80 100644
--- a/res/ethereum/homestead_test.json
+++ b/res/ethereum/homestead_test.json
@@ -3,7 +3,7 @@
 	"engineName": "Ethash",
 	"params": {
 		"accountStartNonce": "0x00",
-		"frontierCompatibilityModeLimit": "0",
+		"frontierCompatibilityModeLimit": 0,
 		"maximumExtraDataSize": "0x20",
 		"minGasLimit": "0x1388",
 		"tieBreakingGas": false,
diff --git a/res/ethereum/morden.json b/res/ethereum/morden.json
index 32fed0cab..cdcf8c7dc 100644
--- a/res/ethereum/morden.json
+++ b/res/ethereum/morden.json
@@ -3,7 +3,7 @@
 	"engineName": "Ethash",
 	"params": {
 		"accountStartNonce": "0x0100000",
-		"frontierCompatibilityModeLimit": "0xDBBA0",
+		"frontierCompatibilityModeLimit": "0xdbba0",
 		"maximumExtraDataSize": "0x20",
 		"tieBreakingGas": false,
 		"minGasLimit": "0x1388",
diff --git a/res/ethereum/tests b/res/ethereum/tests
index e838fd909..c670b1d8c 160000
--- a/res/ethereum/tests
+++ b/res/ethereum/tests
@@ -1 +1 @@
-Subproject commit e838fd90998fc5502d0b7c9427a4c231f9a6953d
+Subproject commit c670b1d8c9f09593a6758ab2c099360e16c7c25b
diff --git a/src/ethereum/ethash.rs b/src/ethereum/ethash.rs
index 019d764df..4736beb92 100644
--- a/src/ethereum/ethash.rs
+++ b/src/ethereum/ethash.rs
@@ -59,9 +59,14 @@ impl Engine for Ethash {
 	}
 
 	fn schedule(&self, env_info: &EnvInfo) -> Schedule {
+		trace!(target: "client", "Creating schedule. param={:?}, fCML={}", self.spec().engine_params.get("frontierCompatibilityModeLimit"), self.u64_param("frontierCompatibilityModeLimit"));
 		match env_info.number < self.u64_param("frontierCompatibilityModeLimit") {
-			true => Schedule::new_frontier(),
-			_ => Schedule::new_homestead(),
+			true => {
+				Schedule::new_frontier()
+			},
+			_ => {
+				Schedule::new_homestead()
+			},
 		}
 	}
 
@@ -178,12 +183,13 @@ impl Ethash {
 			}
 		}
 		else {
+			trace!(target: "ethash", "Calculating difficulty parent.difficulty={}, header.timestamp={}, parent.timestamp={}", parent.difficulty, header.timestamp, parent.timestamp);
+			//block_diff = parent_diff + parent_diff // 2048 * max(1 - (block_timestamp - parent_timestamp) // 10, -99)
 			let diff_inc = (header.timestamp - parent.timestamp) / 10;
 			if diff_inc <= 1 {
 				parent.difficulty + parent.difficulty / From::from(2048) * From::from(1 - diff_inc)
-			}
-			else {
-				parent.difficulty - parent.difficulty / From::from(2048) * From::from(max(diff_inc - 1, 99))
+			} else {
+				parent.difficulty - parent.difficulty / From::from(2048) * From::from(min(diff_inc - 1, 99))
 			}
 		};
 		target = max(min_difficulty, target);
diff --git a/src/lib.rs b/src/lib.rs
index 8dd02b3bc..e084635dd 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -91,6 +91,8 @@ extern crate evmjit;
 #[macro_use]
 extern crate ethcore_util as util;
 extern crate crossbeam;
+#[macro_use]
+extern crate lazy_static;
 
 // NOTE: Add doc parser exception for these pub declarations.
 
diff --git a/src/spec.rs b/src/spec.rs
index f4166eab2..4d342f713 100644
--- a/src/spec.rs
+++ b/src/spec.rs
@@ -16,7 +16,7 @@ pub fn gzip64res_to_json(source: &[u8]) -> Json {
 	Json::from_str(&s).expect("Json is invalid")
 }
 
-/// Convert JSON value to equivlaent RLP representation.
+/// Convert JSON value to equivalent RLP representation.
 // TODO: handle container types.
 fn json_to_rlp(json: &Json) -> Bytes {
 	match *json {
@@ -77,6 +77,10 @@ pub struct Spec {
 	pub gas_used: U256,
 	/// TODO [Gav Wood] Please document me
 	pub timestamp: u64,
+	/// Transactions root of the genesis block. Should be SHA3_NULL_RLP.
+	pub transactions_root: H256,
+	/// Receipts root of the genesis block. Should be SHA3_NULL_RLP.
+	pub receipts_root: H256,
 	/// TODO [arkpar] Please document me
 	pub extra_data: Bytes,
 	/// TODO [Gav Wood] Please document me
@@ -120,11 +124,11 @@ impl Spec {
 			timestamp: self.timestamp,
 			number: 0,
 			author: self.author.clone(),
-			transactions_root: SHA3_NULL_RLP.clone(),
+			transactions_root: self.transactions_root.clone(),
 			uncles_hash: RlpStream::new_list(0).out().sha3(),
 			extra_data: self.extra_data.clone(),
 			state_root: self.state_root().clone(),
-			receipts_root: SHA3_NULL_RLP.clone(),
+			receipts_root: self.receipts_root.clone(),	
 			log_bloom: H2048::new().clone(),
 			gas_used: self.gas_used.clone(),
 			gas_limit: self.gas_limit.clone(),
@@ -172,6 +176,8 @@ impl Spec {
 		};
 		
 		self.parent_hash = H256::from_json(&genesis["parentHash"]);
+		self.transactions_root = genesis.find("transactionsTrie").and_then(|_| Some(H256::from_json(&genesis["transactionsTrie"]))).unwrap_or(SHA3_NULL_RLP.clone());
+		self.receipts_root = genesis.find("receiptTrie").and_then(|_| Some(H256::from_json(&genesis["receiptTrie"]))).unwrap_or(SHA3_NULL_RLP.clone());
 		self.author = Address::from_json(&genesis["coinbase"]);
 		self.difficulty = U256::from_json(&genesis["difficulty"]);
 		self.gas_limit = U256::from_json(&genesis["gasLimit"]);
@@ -248,6 +254,8 @@ impl FromJson for Spec {
 			gas_limit: U256::from_str(&genesis["gasLimit"].as_string().unwrap()[2..]).unwrap(),
 			gas_used: U256::from(0u8),
 			timestamp: u64::from_str(&genesis["timestamp"].as_string().unwrap()[2..]).unwrap(),
+			transactions_root: SHA3_NULL_RLP.clone(),
+			receipts_root: SHA3_NULL_RLP.clone(),
 			extra_data: genesis["extraData"].as_string().unwrap()[2..].from_hex().unwrap(),
 			genesis_state: state,
 			seal_fields: seal_fields,
diff --git a/src/tests/chain.rs b/src/tests/chain.rs
index 84ca35058..d56d99491 100644
--- a/src/tests/chain.rs
+++ b/src/tests/chain.rs
@@ -1,3 +1,6 @@
+use std::env;
+use log::{LogLevelFilter};
+use env_logger::LogBuilder;
 use super::test_common::*;
 use client::{BlockChainClient,Client};
 use pod_state::*;
@@ -10,7 +13,24 @@ pub enum ChainEra {
 	Homestead,
 }
 
+lazy_static! {
+	static ref LOG_DUMMY: bool = {
+		let mut builder = LogBuilder::new();
+		builder.filter(None, LogLevelFilter::Info);
+
+		if let Ok(log) = env::var("RUST_LOG") {
+			builder.parse(&log);
+		}
+
+		if let Ok(_) = builder.init() {
+			println!("logger initialized");
+		}
+		true
+	};
+}
+
 pub fn json_chain_test(json_data: &[u8], era: ChainEra) -> Vec<String> {
+	let _ = LOG_DUMMY.deref();
 	let json = Json::from_str(::std::str::from_utf8(json_data).unwrap()).expect("Json is invalid");
 	let mut failed = Vec::new();
 
@@ -35,10 +55,13 @@ pub fn json_chain_test(json_data: &[u8], era: ChainEra) -> Vec<String> {
 			spec.set_genesis_state(s);
 			spec.overwrite_genesis(test.find("genesisBlockHeader").unwrap());
 			assert!(spec.is_state_root_valid());
+			let genesis_hash = spec.genesis_header().hash();
+			assert_eq!(genesis_hash, H256::from_json(&test.find("genesisBlockHeader").unwrap()["hash"]));
 
 			let temp = RandomTempPath::new();
 			{
 				let client = Client::new(spec, temp.as_path(), IoChannel::disconnected()).unwrap();
+				assert_eq!(client.chain_info().best_block_hash, genesis_hash);
 				for (b, is_valid) in blocks.into_iter() {
 					if Block::is_good(&b) {
 						let _ = client.import_block(b.clone());