diff --git a/websocket-sharp/Ext.cs b/websocket-sharp/Ext.cs
index cb6565fc1..d0d560c0d 100644
--- a/websocket-sharp/Ext.cs
+++ b/websocket-sharp/Ext.cs
@@ -69,6 +69,7 @@ public static class Ext
     private static readonly byte[] _last = new byte[] { 0x00 };
     private static readonly int    _retry = 5;
     private const string           _tspecials = "()<>@,;:\\\"/[]?={} \t";
+    private static UTF8Encoding    _utf8 = new UTF8Encoding (false, true);
 
     #endregion
 
@@ -156,7 +157,7 @@ internal static byte[] Append (this ushort code, string reason)
       var ret = code.InternalToByteArray (ByteOrder.Big);
       if (reason != null && reason.Length > 0) {
         var buff = new List<byte> (ret);
-        buff.AddRange (Encoding.UTF8.GetBytes (reason));
+        buff.AddRange (_utf8.GetBytes (reason));
         ret = buff.ToArray ();
       }
 
@@ -496,18 +497,14 @@ internal static bool IsPortNumber (this int value)
 
     internal static bool IsReserved (this ushort code)
     {
-      return code == 1004
-             || code == 1005
-             || code == 1006
-             || code == 1015;
+      return !( (code > 999 && code < 1004)
+                || (code > 1006 && code < 1012)
+                || (code > 2999 && code < 5000) );
     }
 
     internal static bool IsReserved (this CloseStatusCode code)
     {
-      return code == CloseStatusCode.Undefined
-             || code == CloseStatusCode.NoStatus
-             || code == CloseStatusCode.Abnormal
-             || code == CloseStatusCode.TlsHandshakeFailure;
+      return IsReserved ((ushort)code);
     }
 
     internal static bool IsSupported (this byte opcode)
@@ -961,7 +958,7 @@ internal static bool TryGetUTF8DecodedString (this byte[] bytes, out string s)
       s = null;
 
       try {
-        s = Encoding.UTF8.GetString (bytes);
+        s = _utf8.GetString (bytes);
       }
       catch {
         return false;
@@ -975,7 +972,7 @@ internal static bool TryGetUTF8EncodedBytes (this string s, out byte[] bytes)
       bytes = null;
 
       try {
-        bytes = Encoding.UTF8.GetBytes (s);
+        bytes = _utf8.GetBytes (s);
       }
       catch {
         return false;
@@ -1018,17 +1015,12 @@ internal static string Unquote (this string value)
 
     internal static string UTF8Decode (this byte[] bytes)
     {
-      try {
-        return Encoding.UTF8.GetString (bytes);
-      }
-      catch {
-        return null;
-      }
+      return _utf8.GetString (bytes);
     }
 
     internal static byte[] UTF8Encode (this string s)
     {
-      return Encoding.UTF8.GetBytes (s);
+      return _utf8.GetBytes (s);
     }
 
     internal static void WriteBytes (this Stream stream, byte[] bytes, int bufferLength)
diff --git a/websocket-sharp/MessageEventArgs.cs b/websocket-sharp/MessageEventArgs.cs
index adf7391aa..445283425 100644
--- a/websocket-sharp/MessageEventArgs.cs
+++ b/websocket-sharp/MessageEventArgs.cs
@@ -61,6 +61,7 @@ internal MessageEventArgs (WebSocketFrame frame)
     {
       _opcode = frame.Opcode;
       _rawData = frame.PayloadData.ApplicationData;
+      setData ();
     }
 
     internal MessageEventArgs (Opcode opcode, byte[] rawData)
@@ -70,6 +71,7 @@ internal MessageEventArgs (Opcode opcode, byte[] rawData)
 
       _opcode = opcode;
       _rawData = rawData;
+      setData ();
     }
 
     #endregion
@@ -103,7 +105,6 @@ internal Opcode Opcode {
     /// </value>
     public string Data {
       get {
-        setData ();
         return _data;
       }
     }
@@ -152,7 +153,6 @@ public bool IsText {
     /// </value>
     public byte[] RawData {
       get {
-        setData ();
         return _rawData;
       }
     }
diff --git a/websocket-sharp/WebSocket.cs b/websocket-sharp/WebSocket.cs
index 7effc8852..5cca863bb 100644
--- a/websocket-sharp/WebSocket.cs
+++ b/websocket-sharp/WebSocket.cs
@@ -1065,6 +1065,11 @@ private bool checkReceivedFrame (WebSocketFrame frame, out string message)
         return false;
       }
 
+      if (frame.Opcode == 0x0 && !_inContinuation) {
+        message = "A continuation frame has been received but there is nothing to continue.";
+        return false;
+      }
+
       if (frame.Rsv2 == Rsv.On) {
         message = "The RSV2 of a frame is non-zero without any negotiation for it.";
         return false;
@@ -1575,8 +1580,19 @@ private bool ping (byte[] data)
 
     private bool processCloseFrame (WebSocketFrame frame)
     {
-      var payload = frame.PayloadData;
-      close (payload, !payload.HasReservedCode, false, true);
+      try {
+        PayloadData payload;
+
+        if (frame.PayloadData.Length > 1)
+          payload = new PayloadData (frame.PayloadData.Code, frame.PayloadData.Reason);
+        else
+          payload = frame.PayloadData;
+
+        close (payload, !payload.HasReservedCode, false, true);
+      }
+      catch {
+        close (1002, String.Empty);
+      }
 
       return false;
     }