Well.... was a good idea to move away from this HD5970... I have no stability issue with my quad sli today, more happy with it than with my HD5970. Hope you'll find a fix soon jcool, it's an unpleasant situation! And the worst is that because of the watercooling, you are not able to claim for RMA normally. Grrr.... Are you sure you can't mount the stock cooler on a very clean manner to claim for RMA?