When I add some one to my buddy list I have to restart iChat to be able to see they are online. (even though I can talk to them). How can I fix this issue?
You could try adding them to the Address Book application (which you launch separately), and THEN adding them to iChat by selecting them from your Address Book.
Is this all the time? Sometimes the AIM server is really screwed up and things work really oddly. I would recommend to try adding someone in another few days and see if the problem still exists.