ok. Please reply here when you get the new Mobo and tell us if it is fixed or not. Hello again! It's taken forever, but I finally got myself a brand new mobo. My supplier refused the RMA claming it was my own fault that some pins had been, quote: "Bent out of shape." When I look back onto the CPU socket there is several pins missing, and nowhere to be found, so I take out my jewellers lupe to see if I can spot the break points, and the pins are missing entirely. Called ASUS and got a man to come pick the board up, and he gave me a Z77 Sabertooth in return, as a way of saying "We're sorry." Happy to relay that the CPU is working flawlessly, just ran Prime95 for 9 hours without a glitch. So those pins missing were the culprits.