Ok,
In iChat Menu Preferences > Accounts you are using the Plus Button to add an account ?
In that pop up that appears you are Choosing Google Talk ?
(It is in here you are entering your Googletalk name as it appears on the Google Web pages)
These are iChat 3 pics
http://www.google.com/support/talk/bin/answer.py?answer=24076
In iChat 3 you had to choose Jabber and later change the Server Name to talk.google.com
Check the Server Setting tab
And the settings there. If SSL is On it will/should list port 5223
If it is Off then port 5222
Of course if you are using Port Forwarding in your Routing device then these two ports plus 5220 need to be open.
UPnP will open the ports the app needs when the app needs them.
8:36 PM Thursday; October 15, 2009
Please, if posting Logs, do not post any Log info after the line "Binary Images for iChat"