Jonathan Schiller said:
This is going to be a hard troubleshoot, as you already know. Keep in mind the kernel event id 41 fault could also mean that any one of your components is pulling or pushing the wrong amount of power. Have you tried swapping the gpu? Or changing the pci/pcie slots your cards are in? I have had one similar problem like this. At the end it was 1 pcie pin shorting my gpu, but for some reason only under load. Just keep in mind electricity can be a finicky thing, just because you are stable with 12v on 200 watts dose not mean you will be stable on 12v at 600 watts.
Well, I got 'lucky'. The PSU was the problem: Ended up ordering a new EVGA P2 unit, and blam, no more problems. Was able to figure this out because an old raidmax thrown in there fixed all the problems.
You were correct, the load voltages on the dying PSU were nothing like idle. Thanks@!!!