Keep getting "Disconnected (Remote host closes socket)&

[SYunker]

* Looking up **************
* Connecting to *********** (************) port 6667...
* Connected. Now logging in...
* Disconnected (Remote host closed socket).

What does this mean? I've opened port 6667 on our firewall, and my xchat connects to other servers fine.

Is there some sort of log I might be able to share with everyone?