In Painkiller and Age of Empires III demo the screen locks up, goes black for a few secs, and VPU recover kicks in. After a couple times of this, I have to reboot. It doesnt happen on HL2, Farcry, BF2 and lots of others. Im using Catalyst 5.8, after using Drivercleaner (per FAQ guidelines). It's happened on Painkiller on all the recent catalyst drivers too. Any suggestions?