.i think that i had a DEFECTIVE 9650...outward sign was core #0 was stuck
Hope you've tracked it down then. my 1st E6600 i got last Jan was faulty, took a while to track down, rma on commando 1st , got new one still same instability, even at stock. So took e6600 for rma, got new one sweet as a nut. Talking to the tech support guy in the store & was only the 2nd person to get a faulty one. Their the equiivalent of newegg here in the uk. Scan

i am going to type a letter to Intel headquarters to complain about the lack of support and not fulfilling their warranty.
Hehe give them hell

take care