Help!

Hello everybody I bought a Dell Studio 540 and I downloaded a few demos from Steam like Arma 2. Whenever I move my mouse in most games the white clouds above me starts to flash and then stop, however in less intensed games like America's Army 3, the white clouds seem to disappear. This is a pretty new Desktop and I want to know what's wrong with it. The GPU normally goes up to 60-80 degree celsius when I play games, and I am really want to know if it's damaged and what's wrong with it.

Specs
Processor- Q8200 2.33ghz
Graphics Card- ATI Radeon HD4670
Monitor- Samsung P2250G 22"

Thanks.

ok.

the 4670 isnt a ''uber gaming card'' but its a rather good one. A card that should b able to play pretty much every game at 1280x1024 on rather good settings. Simple question ever tried removing the drivers you got on it, and reinstalling the ones from ati's site. (so remove drivers, reboot and install new ones, reboot again, then test game)

Also dont think the heat is a issue, i have one and it idles at 50ish and goes up to 90 in furmark