bsod errors

Help!
I have built my new system around my new ecs C19-A SLI mobo but after installing windows I have periodic bsod errors that happen normally at periods of high load.
The errors are different each time and range from page "error in non paged area" bsods to "IRQ not less or equal"
My system is:
C19-A SLI mobo
p4 630 3.0ghz 800fsb 2mb cache
1gb infineon 533mhz 4300 ddr2 ram
160gb seagate hd
xfx 7900gs 256mb vga
570watt branded psu

The processor runs at 65 degrees at full load and 49 idle and system temp is low at about 40.

I have used memcheck which found no errors in the ram, the hard drive works fine with no errors in another system, the errors occur without the vga card plugged in and on a previous mobo I was having similar problems. These errors also happened during windows xp install so it is not an issue with any drivers I have installed.

What I need to know is whether these errors could be caused by a faulty processor and how to check without obtaining a new one. Is there a way to isolate exactly which component is to blame by reading the error logs in event viewer? Could the temp of the ram be to blame as errors occur at high load after about 30 minutes.

Any help with this would be greatly appreciated as I want to play Medievel Total War for more than 10 minutes!!!!!

Thanks guys!