Can connect to a server but...

[Shirewolf]

I I get disconnected right away when I try to join a channel. ANY CHANNEL. The only way I can get on EFnet now is through mibbit. When I use Mirc I can connect to other servers, but no efnet servers. I've tried most of them and I can connect but again, I get disconnected right away when I try to join a channel. I get this:

"03[05:26] Local host: unknown (67.218.118.62)
-
02[05:26] * Disconnected
Session Close: Mon Nov 15 05:26:17 2010"

I also get this at times:

"03[05:28] Local host: irc.underworld.no (128.39.65.230)
-
03[05:29] * [10053] Software caused connection abort"

can anyone help?:( I'm clueless as to what to do.