Desktop freeze with 270.x drivers, KDE 4 and Compiz
Independently which window manager i use (Compiz or KWin with 3D effects) all desktop freeze immediately after window manager start. System doesn't hang because I can move mouse cursor. If I start KDE without compositing and after that run Compiz from console and after freeze I kill it, everything unfreeze.
It only happens with new 270.x driver series.