computer freezes at MB splash screen

I been searching around for solutions to this but I haven't had much luck with them:

system:
cpu - Intel Q6600 2.4ghz
mb - asus p5n32-e sli plus
ram - 4gb ocz ddr2-800
vid - bfg 8800 gts 640mb

problem:
The computer was built about 2 weeks ago and has been working perfectly until now:
yesterday I installed new beta video card drivers from nvidia and when I restarted, my computer froze on the motherboard splash screen. there was the usual message that I could press delete to enter setup or tab to see post results, however neither of these respond. If I restart I get the same thing repeatedly and if I restart and hold del/tab/f8 the message will change but it will still freeze (holding tab seems to freeze on the next screen where it tests memory and shows the energy star logo).

This happened last night and it booted properly after I removed 2 gigs of ram. I then replaced all 4 gigs of ram and it still booted properly. However this morning that does not fix it. I also removed all ram from the MB and it did not make it to the splash screen, instead there was no monitor signal. (I should mention now that I don't seem to get any post beeps even when it was working properly, I assume the onboard sound is not hooked up).

I'm currently away from that computer but when I get home I'm going to try a different power supply to see if that fixes anything. I'm also concerned it might be a problem with the motherboard itself and it will need to be replaced.

If anyone has any insight into this it would be really appreciated. Thanks!