I just RMA'd an unstable motherboard that's due back any day now. In the past I've had good luck with RMAing products with all but one instance. One time I sent a motherboard to be RMA'd. The company just sent the same board back to me and acted like they had fixed it. I sent it back and it happened again. I had to hit the motherboard with a taser to kill it so I could get another one.
I'm just curious how they test. Do they just plug a CPU and memory on and if it posts do they consider it "OK" and send it back or do they plug diagnostic equipment up and test the board for errors and what not?