Mine

ERROR [ ]: System.IO.IOException: Write failure ---> System.Net.Sockets.SocketException: The socket has been shut down
  at System.Net.Sockets.Socket.Send (System.Byte[] buf, Int32 offset, Int32 size, SocketFlags flags) [0x00000] 
  at System.Net.Sockets.NetworkStream.Write (System.Byte[] buffer, Int32 offset, Int32 size) [0x00000] --- End of inner exception stack trace ---

  at System.Net.Sockets.NetworkStream.Write (System.Byte[] buffer, Int32 offset, Int32 size) [0x00000] 
  at System.IO.StreamWriter.FlushBytes () [0x00000] 
  at System.IO.StreamWriter.Flush () [0x00000] 
  at OpenSim.Region.Environment.Modules.IRCChatModule.PingRun () [0x00000] 
  at (wrapper delegate-invoke) System.MulticastDelegate:invoke_void ()