exception trying to connect to socket.io server

trying to connect to the url "ws://my.server.ip:3000/" fails.

If I enable logging, I get the following

08/10/2014 14:51:33|Warn |Logger.set_File|The current path to the log file has been changed to c:\temp\log.txt.
08/10/2014 14:51:33|Debug|WebSocket.send|A WebSocket connection request to ws://my.server.ip:3000/:
                      GET / HTTP/1.1
                      User-Agent: websocket-sharp/1.0
                      Upgrade: websocket
                      Connection: Upgrade
                      Host: my.server.ip
                      Sec-WebSocket-Key: xVS7ewLwqpJqe+12F6BouQ==
                      Sec-WebSocket-Version: 13
08/10/2014 14:51:33|Fatal|WebSocket.acceptException|WebSocketSharp.WebSocketException: An exception has occurred while receiving a handshake. ---> System.ArgumentOutOfRangeException: Specified argument was out of the range of valid values.
                      Parameter name: value
                         at WebSocketSharp.Ext.EqualsWith(Int32 value, Char c, Action`1 action)
                         at WebSocketSharp.WebSocketStream.readHandshakeHeaders(Stream stream)
                         at WebSocketSharp.WebSocketStream.ReadHandshake[T](Func`2 parser, Int32 millisecondsTimeout)
                         --- End of inner exception stack trace ---
                         at WebSocketSharp.WebSocketStream.ReadHandshake[T](Func`2 parser, Int32 millisecondsTimeout)
                         at WebSocketSharp.WebSocketStream.ReadHandshakeResponse()
                         at WebSocketSharp.WebSocket.receiveHandshakeResponse()
                         at WebSocketSharp.WebSocket.sendHandshakeRequest(HandshakeRequest request)
                         at WebSocketSharp.WebSocket.sendHandshakeRequest()
                         at WebSocketSharp.WebSocket.doHandshake()
                         at WebSocketSharp.WebSocket.connect()
08/10/2014 14:51:33|Debug|WebSocket.closeHandshake|Was clean?: False
                      sent: False received: True

Start at WebSocket.connect and follow the handshake path through WebSocket.sendHandshakeRequest, WebSocket.receiveHandshakeResponse, and WebSocketStream.readHandshakeHeaders. Reproduce the connection against the reported socket.io server and inspect the logged handshake response. Done should include a confirmed cause for the parsing exception and a verified resolution or clearly documented incompatibility.