Hmm... I think you should have a little luck getting 3.6 to run on less volts. Not saying stock volts like mine, but less that 1.425 set. Try using the htt to overclock on the 15x or 16x multi. You might be having the same problem I did with the multipliers not working correctly. Since your on x64 though that might be why it needs more volts to do everything.