Windowed mode doesn't allow CFX or SLI to work... and since i'm running 2x6990 (that's 4 GPU cores) AND Eyefinity setup, I can't just allow Full Screen to not work. The whole reason I got dual 6990 and 3 screens was for FFXIV, lol...

I re-installed SP1 again and full screen mode worked again. Not sure what happened... But it is working now