On Thursday, there was apparently a server side issue at AOL affecting some (but not all) AOL/AIM/ICQ users on all clients, including Adium. If you were already logged on, you didn't have a problem getting your buddy list or sending or receiving IMs or locating people. For a couple of hours in the early afternoon eastern time, if you were in an unlucky fraction of people who signed on, you didn't get your buddy list and couldn't IM or locate people. You also might have hung while logging in - you would have signed in, but the spinning black square in the Dock icon would have been remained while Adium tried to retrieve your buddy list.

Apparently AOL fixed it across the board around 3:30/3:45 eastern time. Not everybody signing on during the 2 hours or so was affected; it seems only about a third or so had the problems, and the other two thirds had no problems at all. No buddy list information should have lost, even for "recent buddies".