Trillian is really kewl allowing you to use bunch of instant messaging stuff, being unable to connect to one of them may be caused by running a firewall set up by a LAN administrator(they are sometimes a bit reluctant to allow these Instant Mess proggies) which does not allow an outgoing connection on certain ports(like 6667-IRC or 3001 and 3004 in the case of Trillian ICQ), or maybe your ISP PROXY may refuse connection but that would be highly unlike.