diff --git a/TimberWinR.ServiceHost/Properties/AssemblyInfo.cs b/TimberWinR.ServiceHost/Properties/AssemblyInfo.cs
index 86c588b..bccff3a 100644
--- a/TimberWinR.ServiceHost/Properties/AssemblyInfo.cs
+++ b/TimberWinR.ServiceHost/Properties/AssemblyInfo.cs
@@ -32,5 +32,5 @@ using System.Runtime.InteropServices;
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
 // [assembly: AssemblyVersion("1.0.*")]
-[assembly: AssemblyVersion("1.3.20.0")]
-[assembly: AssemblyFileVersion("1.3.20.0")]
+[assembly: AssemblyVersion("1.3.21.0")]
+[assembly: AssemblyFileVersion("1.3.21.0")]
diff --git a/TimberWinR/Inputs/UdpInputListener.cs b/TimberWinR/Inputs/UdpInputListener.cs
index d7f0cd7..728e387 100644
--- a/TimberWinR/Inputs/UdpInputListener.cs
+++ b/TimberWinR/Inputs/UdpInputListener.cs
@@ -13,8 +13,8 @@ namespace TimberWinR.Inputs
 {
     public class UdpInputListener : InputListener
     {      
-        private UdpClient _udpListenerV6;      
-        private readonly Thread _listenThreadV6;
+        private UdpClient _udpListenerV4;      
+        private readonly Thread _listenThreadV4;
 
         private readonly int _port;
         private long _receivedMessages;
@@ -36,13 +36,11 @@ namespace TimberWinR.Inputs
         public UdpInputListener(CancellationToken cancelToken, int port = 5140)
             : base(cancelToken, "Win32-Udp")
         {
-            _port = port;
-     
- 
+            _port = port;     
             _receivedMessages = 0;
 
-            _listenThreadV6 = new Thread(StartListener);
-            _listenThreadV6.Start();
+            _listenThreadV4 = new Thread(StartListener);
+            _listenThreadV4.Start();
         }
 
 
@@ -51,31 +49,21 @@ namespace TimberWinR.Inputs
             LogManager.GetCurrentClassLogger().Info("Shutting Down {0}", InputType);
 
             // close UDP listeners, which will end the listener threads          
-            _udpListenerV6.Close();
+            _udpListenerV4.Close();
 
             // wait for completion of the threads         
-            _listenThreadV6.Join();          
+            _listenThreadV4.Join();          
 
             base.Shutdown();
         }
 
         private void StartListener()
         {                      
-            var groupV6 = new IPEndPoint(IPAddress.IPv6Any, _port);
-            // Create the socket as IPv6
-            var dualModeSocket = new Socket(AddressFamily.InterNetworkV6, SocketType.Dgram, ProtocolType.Udp);
-            
-            //
-            // Now, disable the IPV6only flag to make it compatable with both ipv4 and ipv6
-            // See: http://blogs.msdn.com/b/malarch/archive/2005/11/18/494769.aspx
-            //
-            dualModeSocket.SetSocketOption(SocketOptionLevel.IPv6, SocketOptionName.IPv6Only, 0);
-            dualModeSocket.Bind(groupV6);
+            var groupV4 = new IPEndPoint(IPAddress.Any, _port);
 
-            _udpListenerV6 = new UdpClient();
-            _udpListenerV6.Client = dualModeSocket;
-
-            LogManager.GetCurrentClassLogger().Info("Udp Input on Port {0} Ready", groupV6);
+            _udpListenerV4 = new UdpClient(_port);            
+    
+            LogManager.GetCurrentClassLogger().Info("Udp Input on Port {0} Ready", groupV4);
 
             string lastMessage = "";
             try
@@ -84,13 +72,18 @@ namespace TimberWinR.Inputs
                 {
                     try
                     {
-                        byte[] bytes = _udpListenerV6.Receive(ref groupV6);  
+                        byte[] bytes = _udpListenerV4.Receive(ref groupV4);  
                         var data = Encoding.UTF8.GetString(bytes, 0, bytes.Length);                                                
                         lastMessage = data;
                         var json = JObject.Parse(data);
                         ProcessJson(json);
                         Interlocked.Increment(ref _receivedMessages);                       
                     }
+                    catch(ArgumentException aex)
+                    {
+                        LogManager.GetCurrentClassLogger().Error(aex);
+                        break;
+                    }
                     catch(SocketException)
                     {                       
                         break;
@@ -107,7 +100,7 @@ namespace TimberWinR.Inputs
                         Interlocked.Increment(ref _parsedErrors);
                     }
                 }
-                _udpListenerV6.Close();
+                _udpListenerV4.Close();
             }
             catch (Exception ex)
             {
diff --git a/TimberWinR/ReleaseNotes.md b/TimberWinR/ReleaseNotes.md
index dc95680..5f7e720 100644
--- a/TimberWinR/ReleaseNotes.md
+++ b/TimberWinR/ReleaseNotes.md
@@ -3,6 +3,9 @@ TimberWinR Release Notes
 A Native Windows to Redis/Elasticsearch Logstash Agent which runs as a service.
 
 Version / Date
+### 1.3.21.0 - 04/13/2015
+1. Rolled Udp listener support to V4 only, too many issues with dual mode sockets
+   and hosts file.  If we want to add this back, I will add a Udpv6 input.
 
 ### 1.3.20.0 - 2015-04-03