diff --git a/js/src/modals/ExecuteContract/DetailsStep/detailsStep.js b/js/src/modals/ExecuteContract/DetailsStep/detailsStep.js
index 082fac6a7..b4488729a 100644
--- a/js/src/modals/ExecuteContract/DetailsStep/detailsStep.js
+++ b/js/src/modals/ExecuteContract/DetailsStep/detailsStep.js
@@ -17,7 +17,8 @@
 import React, { Component, PropTypes } from 'react';
 import { MenuItem } from 'material-ui';
 
-import { AddressSelect, Form, Input, InputAddressSelect, Select } from '~/ui';
+import { AddressSelect, Form, Input, Select, TypedInput } from '~/ui';
+import { parseAbiType } from '~/util/abi';
 
 import styles from '../executeContract.css';
 
@@ -74,7 +75,7 @@ export default class DetailsStep extends Component {
 
     const functions = contract.functions
       .filter((func) => !func.constant)
-      .sort((a, b) => a.name.localeCompare(b.name))
+      .sort((a, b) => (a.name || '').localeCompare(b.name || ''))
       .map((func) => {
         const params = (func.abi.inputs || [])
           .map((input, index) => {
@@ -125,56 +126,22 @@ export default class DetailsStep extends Component {
     }
 
     return (func.abi.inputs || []).map((input, index) => {
-      const onChange = (event, value) => onValueChange(event, index, value);
-      const onSelect = (event, _index, value) => onValueChange(event, index, value);
-      const onSubmit = (value) => onValueChange(null, index, value);
+      const onChange = (value) => onValueChange(null, index, value);
       const label = `${input.name}: ${input.type}`;
-      let inputbox;
-
-      switch (input.type) {
-        case 'address':
-          inputbox = (
-            <InputAddressSelect
-              accounts={ accounts }
-              editing
-              label={ label }
-              value={ values[index] }
-              error={ valuesError[index] }
-              onChange={ onChange } />
-          );
-          break;
-
-        case 'bool':
-          const boolitems = ['false', 'true'].map((bool) => {
-            return (
-              <MenuItem
-                key={ bool }
-                value={ bool }
-                label={ bool }>{ bool }</MenuItem>
-            );
-          });
-          inputbox = (
-            <Select
-              label={ label }
-              value={ values[index] ? 'true' : 'false' }
-              error={ valuesError[index] }
-              onChange={ onSelect }>{ boolitems }</Select>
-          );
-          break;
-
-        default:
-          inputbox = (
-            <Input
-              label={ label }
-              value={ values[index] }
-              error={ valuesError[index] }
-              onSubmit={ onSubmit } />
-          );
-      }
 
       return (
-        <div className={ styles.funcparams } key={ index }>
-          { inputbox }
+        <div
+          key={ `${index}_${input.name || ''}` }
+          className={ styles.funcparams }
+        >
+          <TypedInput
+            label={ label }
+            value={ values[index] }
+            error={ valuesError[index] }
+            onChange={ onChange }
+            accounts={ accounts }
+            param={ parseAbiType(input.type) }
+          />
         </div>
       );
     });
diff --git a/js/src/modals/ExecuteContract/executeContract.js b/js/src/modals/ExecuteContract/executeContract.js
index c3b64d738..4a708d17a 100644
--- a/js/src/modals/ExecuteContract/executeContract.js
+++ b/js/src/modals/ExecuteContract/executeContract.js
@@ -23,6 +23,7 @@ import ContentClear from 'material-ui/svg-icons/content/clear';
 import { BusyStep, CompletedStep, Button, IdentityIcon, Modal, TxHash } from '~/ui';
 import { MAX_GAS_ESTIMATION } from '../../util/constants';
 import { validateAddress, validateUint } from '../../util/validation';
+import { parseAbiType } from '~/util/abi';
 
 import DetailsStep from './DetailsStep';
 
@@ -66,7 +67,7 @@ class ExecuteContract extends Component {
     const { contract } = this.props;
     const functions = contract.functions
       .filter((func) => !func.constant)
-      .sort((a, b) => a.name.localeCompare(b.name));
+      .sort((a, b) => (a.name || '').localeCompare(b.name || ''));
 
     this.onFuncChange(null, functions[0]);
   }
@@ -111,7 +112,7 @@ class ExecuteContract extends Component {
         <Button
           key='postTransaction'
           label='post transaction'
-          disabled={ sending || hasError }
+          disabled={ !!(sending || hasError) }
           icon={ <IdentityIcon address={ fromAddress } button /> }
           onClick={ this.postTransaction } />
       ];
@@ -174,23 +175,9 @@ class ExecuteContract extends Component {
   }
 
   onFuncChange = (event, func) => {
-    const values = func.inputs.map((input) => {
-      switch (input.kind.type) {
-        case 'address':
-          return '0x';
-
-        case 'bool':
-          return false;
-
-        case 'bytes':
-          return '0x';
-
-        case 'uint':
-          return '0';
-
-        default:
-          return '';
-      }
+    const values = (func.abi.inputs || []).map((input) => {
+      const parsedType = parseAbiType(input.type);
+      return parsedType.default;
     });
 
     this.setState({
diff --git a/js/src/redux/providers/compilerWorker.js b/js/src/redux/providers/compilerWorker.js
index 247333f5e..f624a4e5f 100644
--- a/js/src/redux/providers/compilerWorker.js
+++ b/js/src/redux/providers/compilerWorker.js
@@ -92,7 +92,7 @@ function findImports (path) {
   return { error: 'File not found' };
 }
 
-function compile (data) {
+function compile (data, optimized = 1) {
   const { sourcecode, build } = data;
   const { longVersion } = build;
 
@@ -109,7 +109,7 @@ function compile (data) {
         '': sourcecode
       };
 
-      const compiled = compiler.compile({ sources: input }, 0, findImports);
+      const compiled = compiler.compile({ sources: input }, optimized, findImports);
 
       self.lastCompile = {
         version: longVersion, result: compiled,
diff --git a/js/src/redux/providers/walletActions.js b/js/src/redux/providers/walletActions.js
index 10f6a278e..8e13ac1a0 100644
--- a/js/src/redux/providers/walletActions.js
+++ b/js/src/redux/providers/walletActions.js
@@ -58,7 +58,7 @@ function modifyOperation (method, address, owner, operation) {
     contract.instance[method]
       .estimateGas(options, values)
       .then((gas) => {
-        options.gas = gas;
+        options.gas = gas.mul(1.2);
         return contract.instance[method].postTransaction(options, values);
       })
       .then((requestId) => {
diff --git a/js/src/views/Contract/Events/events.js b/js/src/views/Contract/Events/events.js
index f0bee3e25..69ae8fd6a 100644
--- a/js/src/views/Contract/Events/events.js
+++ b/js/src/views/Contract/Events/events.js
@@ -15,6 +15,7 @@
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
 import React, { Component, PropTypes } from 'react';
+import { uniq } from 'lodash';
 
 import { Container } from '~/ui';
 
@@ -38,7 +39,10 @@ export default class Events extends Component {
       return null;
     }
 
-    const list = events.map((event) => {
+    const eventsKey = uniq(events.map((e) => e.key));
+    const list = eventsKey.map((eventKey) => {
+      const event = events.find((e) => e.key === eventKey);
+
       return (
         <Event
           key={ event.key }