One more question... Since the power supply was mentioned as an issue, is there any possibility that a dirty power source between the house's circuit panel and the computer's power supply could be causing these crashes? I don't know how to test that though.
Would it be useful to post all your hardware configuration here including your power supply capacity. BSOD's may be either a system or a hardware problem. Please check your hardaware drivers (very important). In my own personal experience, I had some BSOD's some time ago, apparently without any cause. Then I noticed that my power supply was too weak to support my VGA, memo, fans and etc... I bought a new one much more powerful. Since then I only have BSOD's caused by drivers conflicts, you know ?