I've been having a different issue with my 5770 than you guys. With 9.12, 9.12+hotfix, 10.1, and 10.1+hotfix (thought I might as well) I sometimes get a blurry desktop when I'm done gaming. It's not always the full screen, usually just the middle that's fuzzy. It goes away upon restart. Does this at stock and overclocked speeds. Sometimes clocks jump down to 400/900 core/mem while in game. I've forced 2D clocks to 450/900 with no sign of improvement.

The other issue is that I can't enable multicore rendering in L4D2. It creates a horrendous amount of input lag when pressing keys and trying to aim. Problem is non-existent with it off.