Baffling. Check what are the power consumption specs for E6320 vs E8400. I would assume E8400 being a 45nm vs older 65nm E6320 is less power hungry. Both are 65W designs though. As a last test, try updating BIOS. It's just really weird, unless E8400 requires significantly higher amp rating on certain voltage, I see no reason whatsoever that PSU protection should kick in on three separate PSUs (if I'm reading your posts correctly). 65W is peanuts. If BIOS update doesn't work, I would go with redk's suggestion - try another PSU.