I've encountered an error, that basically crashes my system of logs me out. This error happens whenever I click and drag something onscreen. It can be a picture, icon, etc. I can move files and folders, but if I click and drag i get a black screen with writing on it. It's too fast so I cant make out what it says, but than I get an error saying I've encountered a graphic problem and it's asking me if I should run the next session in graphic simple mode. I can click anything at this point and can only force restart. The other option is that I get logged out. I'm using 12.04 with AMD Radeon HD 6630M switchable.
any help? thx