Dom, what drivers are you using? I have a whole cd worth of different Nvidia drivers and I'll let you try it o ut. IRQL_NOT_LESS_OR_EQUAL is basically a driver issue..its usually either ram or video card.

I'm running Windows Longhorn Milestone 5 beta and I get that problem once in a while with my cards. But I narrowed it down to just my ram and/or video card being *****y about my 64bit on 32bit emulation.