diff --git a/Src/Newtonsoft.Json.Tests/Converters/XmlNodeConverterTest.cs b/Src/Newtonsoft.Json.Tests/Converters/XmlNodeConverterTest.cs
index 7fe895d2..4dc32b2b 100644
--- a/Src/Newtonsoft.Json.Tests/Converters/XmlNodeConverterTest.cs
+++ b/Src/Newtonsoft.Json.Tests/Converters/XmlNodeConverterTest.cs
@@ -1,4 +1,4 @@
-#region License
+#region License
 // Copyright (c) 2007 James Newton-King
 //
 // Permission is hereby granted, free of charge, to any person
@@ -1257,6 +1257,50 @@ namespace Newtonsoft.Json.Tests.Converters
   }
 }", json);
     }
+
+    [Test]
+    public void DeserializeNonInt64IntegerValues()
+    {
+      var dict = new Dictionary<string, object> { { "Int16", (short)1 }, { "Float", 2f }, { "Int32", 3 } };
+      var obj = JObject.FromObject(dict);
+      var serializer = JsonSerializer.Create(new JsonSerializerSettings { Converters = { new XmlNodeConverter() { DeserializeRootElementName = "root" } } });
+      using (var reader = obj.CreateReader())
+      {
+        var value = (XmlDocument)serializer.Deserialize(reader, typeof(XmlDocument));
+
+        Assert.AreEqual(@"<root><Int16>1</Int16><Float>2</Float><Int32>3</Int32></root>", value.InnerXml);
+      }
+    }
+
+    [Test]
+    public void DeserializingBooleanValues()
+    {
+      MemoryStream ms = new MemoryStream(System.Text.Encoding.UTF8.GetBytes(@"{root:{""@booleanType"":true}}"));
+      MemoryStream xml = new MemoryStream();
+
+      JsonBodyToSoapXml(ms, xml);
+
+      string xmlString = System.Text.Encoding.UTF8.GetString(xml.ToArray());
+
+      Assert.AreEqual(@"<?xml version=""1.0"" encoding=""utf-8""?><root booleanType=""true"" />", xmlString);
+    }
+
+    static void JsonBodyToSoapXml(Stream json, Stream xml)
+    {
+      Newtonsoft.Json.JsonSerializerSettings settings = new Newtonsoft.Json.JsonSerializerSettings();
+      settings.Converters.Add(new Newtonsoft.Json.Converters.XmlNodeConverter());
+      Newtonsoft.Json.JsonSerializer serializer = Newtonsoft.Json.JsonSerializer.Create(settings);
+      using (Newtonsoft.Json.JsonTextReader reader = new Newtonsoft.Json.JsonTextReader(new System.IO.StreamReader(json)))
+      {
+        XmlDocument doc = (XmlDocument)serializer.Deserialize(reader, typeof(XmlDocument));
+        if (reader.Read() && reader.TokenType != JsonToken.Comment)
+          throw new JsonSerializationException("Additional text found in JSON string after finishing deserializing object.");
+        using (XmlWriter writer = XmlWriter.Create(xml))
+        {
+          doc.Save(writer);
+        }
+      }
+    }
   }
 }
 #endif
\ No newline at end of file
diff --git a/Src/Newtonsoft.Json.Tests/Linq/JArrayTests.cs b/Src/Newtonsoft.Json.Tests/Linq/JArrayTests.cs
index ebf9c958..ff612b56 100644
--- a/Src/Newtonsoft.Json.Tests/Linq/JArrayTests.cs
+++ b/Src/Newtonsoft.Json.Tests/Linq/JArrayTests.cs
@@ -436,5 +436,17 @@ Parameter name: index")]
     {
       JArray.Parse("[1");
     }
+
+    [Test]
+    public void InsertAddEnd()
+    {
+      JArray array = new JArray();
+      array.Insert(0, 123);
+      array.Insert(1, 456);
+
+      Assert.AreEqual(2, array.Count);
+      Assert.AreEqual(123, (int)array[0]);
+      Assert.AreEqual(456, (int)array[1]);
+    }
   }
 }
\ No newline at end of file
diff --git a/Src/Newtonsoft.Json.Tests/Linq/JTokenTests.cs b/Src/Newtonsoft.Json.Tests/Linq/JTokenTests.cs
index c7cf491f..5b2e05b3 100644
--- a/Src/Newtonsoft.Json.Tests/Linq/JTokenTests.cs
+++ b/Src/Newtonsoft.Json.Tests/Linq/JTokenTests.cs
@@ -209,6 +209,9 @@ namespace Newtonsoft.Json.Tests.Linq
     [Test]
     public void Casting()
     {
+      Assert.AreEqual(1L, (long)(new JValue(1)));
+      Assert.AreEqual(2L, (long) new JArray(1, 2, 3)[1]);
+
       Assert.AreEqual(new DateTime(2000, 12, 20), (DateTime)new JValue(new DateTime(2000, 12, 20)));
 #if !PocketPC && !NET20
       Assert.AreEqual(new DateTimeOffset(2000, 12, 20, 23, 50, 10, TimeSpan.Zero), (DateTimeOffset)new JValue(new DateTimeOffset(2000, 12, 20, 23, 50, 10, TimeSpan.Zero)));
diff --git a/Src/Newtonsoft.Json.Tests/PerformanceTests.cs b/Src/Newtonsoft.Json.Tests/PerformanceTests.cs
index 23536a5d..89fcdcdc 100644
--- a/Src/Newtonsoft.Json.Tests/PerformanceTests.cs
+++ b/Src/Newtonsoft.Json.Tests/PerformanceTests.cs
@@ -126,14 +126,14 @@ namespace Newtonsoft.Json.Tests
     public void BuildJObject()
     {
       JObject o = new JObject();
-      for (int i = 0; i < 200; i++)
+      for (int i = 0; i < 50; i++)
       {
         o[i.ToString()] = i;
       }
       string jsonText = o.ToString();
 
       // this is extremely slow with 5000 interations
-      int interations = 100;
+      int interations = 1000;
 
       TimeOperation(() =>
       {
diff --git a/Src/Newtonsoft.Json.Tests/Properties/AssemblyInfo.cs b/Src/Newtonsoft.Json.Tests/Properties/AssemblyInfo.cs
index d9aade55..d3883b4a 100644
--- a/Src/Newtonsoft.Json.Tests/Properties/AssemblyInfo.cs
+++ b/Src/Newtonsoft.Json.Tests/Properties/AssemblyInfo.cs
@@ -66,5 +66,5 @@ using System.Runtime.InteropServices;
 // by using the '*' as shown below:
 [assembly: AssemblyVersion("4.0.3.0")]
 #if !PocketPC
-[assembly: AssemblyFileVersion("4.0.3.14202")]
+[assembly: AssemblyFileVersion("4.0.3.14301")]
 #endif
diff --git a/Src/Newtonsoft.Json.Tests/Serialization/JsonSerializerTest.cs b/Src/Newtonsoft.Json.Tests/Serialization/JsonSerializerTest.cs
index 3e0b170d..c7386956 100644
--- a/Src/Newtonsoft.Json.Tests/Serialization/JsonSerializerTest.cs
+++ b/Src/Newtonsoft.Json.Tests/Serialization/JsonSerializerTest.cs
@@ -24,11 +24,15 @@
 #endregion
 
 using System;
+#if !(NET35 || NET20 || SILVERLIGHT || WINDOWS_PHONE)
+using System.Collections.Concurrent;
+#endif
 using System.Collections.Generic;
 #if !SILVERLIGHT && !PocketPC && !NET20
 using System.ComponentModel.DataAnnotations;
 using System.Configuration;
 using System.Runtime.CompilerServices;
+using System.Runtime.Serialization.Formatters;
 using System.Threading;
 using System.Web.Script.Serialization;
 #endif
@@ -4910,6 +4914,107 @@ keyword such as type of business.""
         Assert.AreEqual(@"{""p"":1}", result);
       }
     }
+
+#if !(NET35 || NET20 || SILVERLIGHT || WINDOWS_PHONE)
+    [Test]
+    public void DeserializeConcurrentDictionary()
+    {
+      IDictionary<string, Component> components = new Dictionary<string, Component>
+        {
+          {"Key!", new Component()}
+        };
+      GameObject go = new GameObject
+        {
+          Components = new ConcurrentDictionary<string, Component>(components),
+          Id = "Id!",
+          Name = "Name!"
+        };
+
+      string originalJson = JsonConvert.SerializeObject(go, Formatting.Indented);
+
+      Assert.AreEqual(@"{
+  ""Components"": {
+    ""Key!"": {}
+  },
+  ""Id"": ""Id!"",
+  ""Name"": ""Name!""
+}", originalJson);
+
+      GameObject newObject = JsonConvert.DeserializeObject<GameObject>(originalJson);
+
+      Assert.AreEqual(1, newObject.Components.Count);
+      Assert.AreEqual("Id!", newObject.Id);
+      Assert.AreEqual("Name!", newObject.Name);
+    }
+#endif
+
+    [Test]
+    public void DeserializeKeyValuePairArray()
+    {
+      string json = @"[ { ""Value"": [ ""1"", ""2"" ], ""Key"": ""aaa"", ""BadContent"": [ 0 ] }, { ""Value"": [ ""3"", ""4"" ], ""Key"": ""bbb"" } ]";
+
+      IList<KeyValuePair<string, IList<string>>> values = JsonConvert.DeserializeObject<IList<KeyValuePair<string, IList<string>>>>(json);
+
+      Assert.AreEqual(2, values.Count);
+      Assert.AreEqual("aaa", values[0].Key);
+      Assert.AreEqual(2, values[0].Value.Count);
+      Assert.AreEqual("1", values[0].Value[0]);
+      Assert.AreEqual("2", values[0].Value[1]);
+      Assert.AreEqual("bbb", values[1].Key);
+      Assert.AreEqual(2, values[1].Value.Count);
+      Assert.AreEqual("3", values[1].Value[0]);
+      Assert.AreEqual("4", values[1].Value[1]);
+    }
+
+    [Test]
+    public void DeserializeNullableKeyValuePairArray()
+    {
+      string json = @"[ { ""Value"": [ ""1"", ""2"" ], ""Key"": ""aaa"", ""BadContent"": [ 0 ] }, null, { ""Value"": [ ""3"", ""4"" ], ""Key"": ""bbb"" } ]";
+
+      IList<KeyValuePair<string, IList<string>>?> values = JsonConvert.DeserializeObject<IList<KeyValuePair<string, IList<string>>?>>(json);
+
+      Assert.AreEqual(3, values.Count);
+      Assert.AreEqual("aaa", values[0].Value.Key);
+      Assert.AreEqual(2, values[0].Value.Value.Count);
+      Assert.AreEqual("1", values[0].Value.Value[0]);
+      Assert.AreEqual("2", values[0].Value.Value[1]);
+      Assert.AreEqual(null, values[1]);
+      Assert.AreEqual("bbb", values[2].Value.Key);
+      Assert.AreEqual(2, values[2].Value.Value.Count);
+      Assert.AreEqual("3", values[2].Value.Value[0]);
+      Assert.AreEqual("4", values[2].Value.Value[1]);
+    }
+
+    [Test]
+    [ExpectedException(typeof (Exception), ExpectedMessage = "Could not deserialize Null to KeyValuePair.")]
+    public void DeserializeNullToNonNullableKeyValuePairArray()
+    {
+      string json = @"[ null ]";
+
+      JsonConvert.DeserializeObject<IList<KeyValuePair<string, IList<string>>>>(json);
+    }
+
+    [Test]
+    public void SerializeUriWithQuotes()
+    {
+      string input = "http://test.com/%22foo+bar%22";
+      Uri uri = new Uri(input);
+      string json = JsonConvert.SerializeObject(uri);
+      Uri output = JsonConvert.DeserializeObject<Uri>(json);
+
+      Assert.AreEqual(uri, output);
+    }
+
+    [Test]
+    public void SerializeUriWithSlashes()
+    {
+      string input = @"http://tes/?a=b\\c&d=e\";
+      Uri uri = new Uri(input);
+      string json = JsonConvert.SerializeObject(uri);
+      Uri output = JsonConvert.DeserializeObject<Uri>(json);
+
+      Assert.AreEqual(uri, output);
+    }
   }
 
   public class UriGuidTimeSpanTestClass
@@ -4920,4 +5025,47 @@ keyword such as type of business.""
     public TimeSpan? NullableTimeSpan { get; set; }
     public Uri Uri { get; set; }
   }
+
+#if !(NET35 || NET20 || SILVERLIGHT || WINDOWS_PHONE)
+  [JsonObject(MemberSerialization.OptIn)]
+  public class GameObject
+  {
+    [JsonProperty]
+    public string Id { get; set; }
+
+    [JsonProperty]
+    public string Name { get; set; }
+
+    [JsonProperty]
+    public ConcurrentDictionary<string, Component> Components;
+
+    public GameObject()
+    {
+      Components = new ConcurrentDictionary<string, Component>();
+    }
+
+  }
+
+  [JsonObject(MemberSerialization.OptIn)]
+  public class Component
+  {
+    [JsonIgnore] // Ignore circular reference 
+    public GameObject GameObject { get; set; }
+
+    public Component()
+    {
+    }
+  }
+
+  [JsonObject(MemberSerialization.OptIn)]
+  public class TestComponent : Component
+  {
+    [JsonProperty]
+    public int MyProperty { get; set; }
+
+    public TestComponent()
+    {
+    }
+  }
+#endif
 }
\ No newline at end of file
diff --git a/Src/Newtonsoft.Json/Converters/KeyValuePairConverter.cs b/Src/Newtonsoft.Json/Converters/KeyValuePairConverter.cs
index e546bdbc..791da1ee 100644
--- a/Src/Newtonsoft.Json/Converters/KeyValuePairConverter.cs
+++ b/Src/Newtonsoft.Json/Converters/KeyValuePairConverter.cs
@@ -42,19 +42,50 @@ namespace Newtonsoft.Json.Converters
     /// <returns>The object value.</returns>
     public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
     {
-      IList<Type> genericArguments = objectType.GetGenericArguments();
+      bool isNullable = ReflectionUtils.IsNullableType(objectType);
+
+      if (reader.TokenType == JsonToken.Null)
+      {
+        if (!isNullable)
+          throw new Exception("Could not deserialize Null to KeyValuePair.");
+
+        return null;
+      }
+
+      Type t = (isNullable)
+       ? Nullable.GetUnderlyingType(objectType)
+       : objectType;
+
+      IList<Type> genericArguments = t.GetGenericArguments();
       Type keyType = genericArguments[0];
       Type valueType = genericArguments[1];
 
-      reader.Read();
-      reader.Read();
-      object key = serializer.Deserialize(reader, keyType);
-      reader.Read();
-      reader.Read();
-      object value = serializer.Deserialize(reader, valueType);
+      object key = null;
+      object value = null;
+
       reader.Read();
 
-      return ReflectionUtils.CreateInstance(objectType, key, value);
+      while (reader.TokenType == JsonToken.PropertyName)
+      {
+        switch (reader.Value.ToString())
+        {
+          case "Key":
+            reader.Read();
+            key = serializer.Deserialize(reader, keyType);
+            break;
+          case "Value":
+            reader.Read();
+            value = serializer.Deserialize(reader, valueType);
+            break;
+          default:
+            reader.Skip();
+            break;
+        }
+
+        reader.Read();
+      }
+
+      return ReflectionUtils.CreateInstance(t, key, value);
     }
 
     /// <summary>
@@ -66,8 +97,12 @@ namespace Newtonsoft.Json.Converters
     /// </returns>
     public override bool CanConvert(Type objectType)
     {
-      if (objectType.IsValueType && objectType.IsGenericType)
-        return (objectType.GetGenericTypeDefinition() == typeof (KeyValuePair<,>));
+      Type t = (ReflectionUtils.IsNullableType(objectType))
+        ? Nullable.GetUnderlyingType(objectType)
+        : objectType;
+
+      if (t.IsValueType && t.IsGenericType)
+        return (t.GetGenericTypeDefinition() == typeof(KeyValuePair<,>));
 
       return false;
     }
diff --git a/Src/Newtonsoft.Json/Converters/XmlNodeConverter.cs b/Src/Newtonsoft.Json/Converters/XmlNodeConverter.cs
index bef5eb6d..d7469e6d 100644
--- a/Src/Newtonsoft.Json/Converters/XmlNodeConverter.cs
+++ b/Src/Newtonsoft.Json/Converters/XmlNodeConverter.cs
@@ -26,6 +26,7 @@
 #if !SILVERLIGHT || WINDOWS_PHONE
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.Xml;
 #if !NET20
 using System.Xml.Linq;
@@ -1194,26 +1195,13 @@ namespace Newtonsoft.Json.Converters
         element.SetAttributeNode(attribute);
       }
 
-      if (reader.TokenType == JsonToken.String)
+      if (reader.TokenType == JsonToken.String
+        || reader.TokenType == JsonToken.Integer
+        || reader.TokenType == JsonToken.Float
+        || reader.TokenType == JsonToken.Boolean
+        || reader.TokenType == JsonToken.Date)
       {
-        element.AppendChild(document.CreateTextNode(reader.Value.ToString()));
-      }
-      else if (reader.TokenType == JsonToken.Integer)
-      {
-        element.AppendChild(document.CreateTextNode(XmlConvert.ToString((long)reader.Value)));
-      }
-      else if (reader.TokenType == JsonToken.Float)
-      {
-        element.AppendChild(document.CreateTextNode(XmlConvert.ToString((double)reader.Value)));
-      }
-      else if (reader.TokenType == JsonToken.Boolean)
-      {
-        element.AppendChild(document.CreateTextNode(XmlConvert.ToString((bool)reader.Value)));
-      }
-      else if (reader.TokenType == JsonToken.Date)
-      {
-        DateTime d = (DateTime)reader.Value;
-        element.AppendChild(document.CreateTextNode(XmlConvert.ToString(d, DateTimeUtils.ToSerializationMode(d.Kind))));
+        element.AppendChild(document.CreateTextNode(ConvertTokenToXmlValue(reader)));
       }
       else if (reader.TokenType == JsonToken.Null)
       {
@@ -1233,6 +1221,39 @@ namespace Newtonsoft.Json.Converters
       }
     }
 
+    private string ConvertTokenToXmlValue(JsonReader reader)
+    {
+      if (reader.TokenType == JsonToken.String)
+      {
+        return reader.Value.ToString();
+      }
+      else if (reader.TokenType == JsonToken.Integer)
+      {
+        return XmlConvert.ToString(Convert.ToInt64(reader.Value, CultureInfo.InvariantCulture));
+      }
+      else if (reader.TokenType == JsonToken.Float)
+      {
+        return XmlConvert.ToString(Convert.ToDouble(reader.Value, CultureInfo.InvariantCulture));
+      }
+      else if (reader.TokenType == JsonToken.Boolean)
+      {
+        return XmlConvert.ToString(Convert.ToBoolean(reader.Value, CultureInfo.InvariantCulture));
+      }
+      else if (reader.TokenType == JsonToken.Date)
+      {
+        DateTime d = Convert.ToDateTime(reader.Value, CultureInfo.InvariantCulture);
+        return XmlConvert.ToString(d, DateTimeUtils.ToSerializationMode(d.Kind));
+      }
+      else if (reader.TokenType == JsonToken.Null)
+      {
+        return null;
+      }
+      else
+      {
+        throw new Exception("Cannot get an XML string value from token type '{0}'.".FormatWith(CultureInfo.InvariantCulture, reader.TokenType));
+      }
+    }
+
     private void ReadArrayElements(JsonReader reader, IXmlDocument document, string propertyName, IXmlNode currentNode, XmlNamespaceManager manager)
     {
       string elementPrefix = MiscellaneousUtils.GetPrefix(propertyName);
@@ -1309,7 +1330,7 @@ namespace Newtonsoft.Json.Converters
                   case '@':
                     attributeName = attributeName.Substring(1);
                     reader.Read();
-                    attributeValue = reader.Value.ToString();
+                    attributeValue = ConvertTokenToXmlValue(reader);
                     attributeNameValues.Add(attributeName, attributeValue);
 
                     string namespacePrefix;
diff --git a/Src/Newtonsoft.Json/JsonConvert.cs b/Src/Newtonsoft.Json/JsonConvert.cs
index 86d20d54..736d6dad 100644
--- a/Src/Newtonsoft.Json/JsonConvert.cs
+++ b/Src/Newtonsoft.Json/JsonConvert.cs
@@ -392,7 +392,10 @@ namespace Newtonsoft.Json
     /// <returns>A JSON string representation of the <see cref="Uri"/>.</returns>
     public static string ToString(Uri value)
     {
-      return '"' + value.ToString() + '"';
+      if (value == null)
+        return Null;
+
+      return ToString(value.ToString());
     }
 
     /// <summary>
diff --git a/Src/Newtonsoft.Json/Linq/JToken.cs b/Src/Newtonsoft.Json/Linq/JToken.cs
index 6d74db13..7bc84f30 100644
--- a/Src/Newtonsoft.Json/Linq/JToken.cs
+++ b/Src/Newtonsoft.Json/Linq/JToken.cs
@@ -418,7 +418,7 @@ namespace Newtonsoft.Json.Linq
       if (v == null || !ValidateBoolean(v, false))
         throw new ArgumentException("Can not convert {0} to Boolean.".FormatWith(CultureInfo.InvariantCulture, GetType(value)));
 
-      return (bool)v.Value;
+      return Convert.ToBoolean(v.Value, CultureInfo.InvariantCulture);
     }
 
 #if !PocketPC && !NET20
@@ -451,7 +451,7 @@ namespace Newtonsoft.Json.Linq
       if (v == null || !ValidateBoolean(v, true))
         throw new ArgumentException("Can not convert {0} to Boolean.".FormatWith(CultureInfo.InvariantCulture, GetType(value)));
 
-      return (bool?)v.Value;
+      return (v.Value != null) ? (bool?)Convert.ToBoolean(v.Value, CultureInfo.InvariantCulture) : null;
     }
 
     /// <summary>
@@ -465,7 +465,7 @@ namespace Newtonsoft.Json.Linq
       if (v == null || !ValidateInteger(v, false))
         throw new ArgumentException("Can not convert {0} to Int64.".FormatWith(CultureInfo.InvariantCulture, GetType(value)));
 
-      return (long)v.Value;
+      return Convert.ToInt64(v.Value, CultureInfo.InvariantCulture);
     }
 
     /// <summary>
@@ -482,7 +482,7 @@ namespace Newtonsoft.Json.Linq
       if (v == null || !ValidateDate(v, true))
         throw new ArgumentException("Can not convert {0} to DateTime.".FormatWith(CultureInfo.InvariantCulture, GetType(value)));
 
-      return (DateTime?)v.Value;
+      return (v.Value != null) ? (DateTime?)Convert.ToDateTime(v.Value, CultureInfo.InvariantCulture) : null;
     }
 
 #if !PocketPC && !NET20
@@ -644,7 +644,7 @@ namespace Newtonsoft.Json.Linq
       if (v == null || !ValidateDate(v, false))
         throw new ArgumentException("Can not convert {0} to DateTime.".FormatWith(CultureInfo.InvariantCulture, GetType(value)));
 
-      return (DateTime)v.Value;
+      return Convert.ToDateTime(v.Value, CultureInfo.InvariantCulture);
     }
 
     /// <summary>
@@ -661,7 +661,7 @@ namespace Newtonsoft.Json.Linq
       if (v == null || !ValidateInteger(v, true))
         throw new ArgumentException("Can not convert {0} to Int64.".FormatWith(CultureInfo.InvariantCulture, GetType(value)));
 
-      return (long?)v.Value;
+      return (v.Value != null) ? (long?)Convert.ToInt64(v.Value, CultureInfo.InvariantCulture) : null;
     }
 
     /// <summary>
@@ -710,7 +710,7 @@ namespace Newtonsoft.Json.Linq
       if (v == null || !ValidateInteger(v, true))
         throw new ArgumentException("Can not convert {0} to UInt32.".FormatWith(CultureInfo.InvariantCulture, GetType(value)));
 
-      return (uint?)v.Value;
+      return (v.Value != null) ? (uint?)Convert.ToUInt32(v.Value, CultureInfo.InvariantCulture) : null;
     }
 
     /// <summary>
@@ -728,7 +728,7 @@ namespace Newtonsoft.Json.Linq
       if (v == null || !ValidateInteger(v, true))
         throw new ArgumentException("Can not convert {0} to UInt64.".FormatWith(CultureInfo.InvariantCulture, GetType(value)));
 
-      return (ulong?)v.Value;
+      return (v.Value != null) ? (ulong?)Convert.ToUInt64(v.Value, CultureInfo.InvariantCulture) : null;
     }
 
     /// <summary>
@@ -742,7 +742,7 @@ namespace Newtonsoft.Json.Linq
       if (v == null || !ValidateFloat(v, false))
         throw new ArgumentException("Can not convert {0} to Double.".FormatWith(CultureInfo.InvariantCulture, GetType(value)));
 
-      return (double)v.Value;
+      return Convert.ToDouble(v.Value, CultureInfo.InvariantCulture);
     }
 
     /// <summary>
@@ -773,7 +773,7 @@ namespace Newtonsoft.Json.Linq
       if (v == null || !ValidateString(v))
         throw new ArgumentException("Can not convert {0} to String.".FormatWith(CultureInfo.InvariantCulture, GetType(value)));
 
-      return (string)v.Value;
+      return (v.Value != null) ? Convert.ToString(v.Value) : null;
     }
 
     /// <summary>
diff --git a/Src/Newtonsoft.Json/Properties/AssemblyInfo.cs b/Src/Newtonsoft.Json/Properties/AssemblyInfo.cs
index ce577bd6..72dfcaa2 100644
--- a/Src/Newtonsoft.Json/Properties/AssemblyInfo.cs
+++ b/Src/Newtonsoft.Json/Properties/AssemblyInfo.cs
@@ -85,7 +85,7 @@ using System.Security;
 // by using the '*' as shown below:
 [assembly: AssemblyVersion("4.0.3.0")]
 #if !PocketPC
-[assembly: AssemblyFileVersion("4.0.3.14202")]
+[assembly: AssemblyFileVersion("4.0.3.14301")]
 #endif
 
 [assembly: CLSCompliant(true)]
diff --git a/Src/Newtonsoft.Json/Serialization/DefaultContractResolver.cs b/Src/Newtonsoft.Json/Serialization/DefaultContractResolver.cs
index 516ad93f..97150f57 100644
--- a/Src/Newtonsoft.Json/Serialization/DefaultContractResolver.cs
+++ b/Src/Newtonsoft.Json/Serialization/DefaultContractResolver.cs
@@ -25,6 +25,9 @@
 
 using System;
 using System.Collections;
+#if !(NET35 || NET20 || SILVERLIGHT || WINDOWS_PHONE)
+using System.Collections.Concurrent;
+#endif
 using System.Collections.Generic;
 using System.ComponentModel;
 #if !(NET35 || NET20 || WINDOWS_PHONE)
@@ -463,12 +466,24 @@ namespace Newtonsoft.Json.Serialization
 
       if (onSerializing != null)
         contract.OnSerializing = onSerializing;
+
       if (onSerialized != null)
         contract.OnSerialized = onSerialized;
+
       if (onDeserializing != null)
         contract.OnDeserializing = onDeserializing;
+
       if (onDeserialized != null)
+      {
+        // ConcurrentDictionary throws an error here so don't use its OnDeserialized - http://json.codeplex.com/discussions/257093
+#if !(NET35 || NET20 || SILVERLIGHT || WINDOWS_PHONE)
+        if (!t.IsGenericType || (t.GetGenericTypeDefinition() != typeof(ConcurrentDictionary<,>)))
+          contract.OnDeserialized = onDeserialized;
+#else
         contract.OnDeserialized = onDeserialized;
+#endif
+      }
+
       if (onError != null)
         contract.OnError = onError;
     }