Sonofander, hopefully you keep in mind that an RMA might not achieve what you have done so far. 80% of the times happen that second boards dont do what the first did.

Do you think it might be drivers problem? Why dont you wait for next week for official quad drivers? Have you tried the new 170.70 leak?

And btw, now that I see your signature, can you tell me, are those thermaltake PSUs good? are they loud?