IRQ - is an interupt request line; it might not be your CPU itself bud.
Look to your RAM on this one man. Run memtest and post up your results.
if you can't run memtest or it doesnt finish, you have your answer on your problem
as I know alot of people are having problems with OCZ, Corsair and 775 board combo's.
more specifically unstable voltages, faulty ram or bad Dimm slots.