I might have encountered this. After logging in successfully, I was able to search the directory (nice work) then I created a group, added eleven or so contacts, changed the name of the group multiple times before signing out.
Then I could not sign back in using official client. Connecting goes beyond "verifying name and password" but then becomes unresponsive. The buddylist window seemed to indicate that the new group was nolonger saved. although, I can sign in successfully using AIM lite. I'm using both within Windows XP FLP on virtual box.
I can provide more details if helpful.
EDIT: also; prices in stock ticker are delayed more than 15 minutes :P
48x48 buddy icons: http://w.iconhell.com/Buddy_Icons.html