CCC 12.1 was the solution for me. I'v tried every driver up to 12.4 and finally gave up on the driver updates until 2.0.
People will say to do things like turn off AA in your game config and then turn it on in CCC. That may help with NPCs loading slow but the issue your having is a different problem that I have also seen first hand.
But yeah, CCC 12.1 works great for me running in fullscreen with crossfireX.

I have also talked to players having luck using the CCC BETA builds. I have not tried any of them, but I do believe ATI now offers them on their website. Good luck.