you're not alone in this misfortune. got mine 3 weeks ago as well and this afternoon when i tried to on it, the 3 red rings of death appeared. i've played accordingly within the timeframe of max 3 hours at one time and still this happened. bought mine in imbi.

I kept mine in one of those hi-fi stacking racks. the roomed is air-conditioned when I'm playing it, and the ventilation is good. Nothing blocking my 360 so the circulation should be good. For god's sake, mine is only 3 weeks old! at least i can say that i've managed to finished my GOW b4 this happened.