Same here.. if you lower AA to medium it will work but I have noticed that once the game exits and you return to it some of the default settings like what resolution is shown and the Frame rate shown get reverted to 800 x 600 and 30 FPS. The odd thing is that it is not showing as 800 x 600 it just says it is. It looks like the resolution you had changed it to last. If you attempt to correct the resolution setting to the correct one it acts as if nothing was changed.. just another bug. Playing with AA on medium is the only fix at the moment.
If you are having a problem with your graphics card or processor or a particular game...Please report it to AMD. Keep in mind that the more reports sent to the Catalyst engineers, the more attention paid. This is the only way things get fixed. Note that all issues must be reproducible, and submitting a "Issue Report" is not a invitation to a dialog with AMD. Don't expect a reply. Just report it and encourage others to do the same.