iChat not connecting

New to Mac. I can't connect to my existing AIM account using iChat. I get an error:

Could not connect to AIM
The connection to the host was unexpectedly lost.

I am using a linksys router and have opened all ports to my iMac. This has never worked. I can't find anything in a search. Can someone please help? Thanks.

im experiencing the exact same problem.... anyone out there know whats going on?

I wish I could help you both, but iChat here works with my AIM account every time and on all my Macs. Hope someone can help you.+

The only time I have had that connect issue is when there were server problems with AIM.

anybody???.....

I'm using Adium - it's great - it combines AIM and MSN onto one program for me.

The problem for me seems to actually be AIM as I can't connect with a PC AIM client either. I am using a linksys wireless router behind a linsys wired router with all ports open on both. So this is not a specific mac issue. Either wireless or home internet problem. No one can help?

Look up this website, iChat FAQs, the answer must be there, it's pretty thorough in going through all the problems chat apps may have.

Edited to add:

BTW, AIM works for me at the moment.