I have installed ATI Catalyst 11.5 driver (fglrx) on my laptop with Ubuntu 11.04 and switchable-graphics technology (ATI Mobility Radeon HD5470). Everything seems ok,
fglrxinfo shows my discrete video card working,
glxgears shows nearly 2000fps, Unity works, no graphical problems etc. But when i try to play games, i.e. Heroes Of Newerth (it has native linux client), my display are all full of graphical blinking artifacts, I think you what I am talking about.
How can I fix this?
Added later: Also I noticed, that when I playing video online via flash player it works good, but when I expand it to full screen, it begins to flash and other annoying artifacts
Added a bit later: The problem is any application(video, game, etc.) in Fullscreen mode. I tried to check off "Full Screen Mode" in game, and there were no artifacts at all, but have some periodic lags