I have a laptop
acer aspire 5745G
330M , core i5 , 2.26 ghz , 4 gb ram
when i am playing heavy games like (GTA IV , Crysis : Warhead , Blur , Red Alert 3 ... and so on)
the Gpu heats quickly and the laptop shutsdown after a short while , and I can hear the fan running too fast .
the strange in that , Call Of Duty : modern wardare 2 runs super perfect , all hight , and no shutdowns !
i bought it 1.5 month ago , and i can say "the dust" isn't a reason...