Alright, I'm trying to get my E8500 stable at 4.2Ghz, but Prime 95 (x64) fails within 5 seconds on Worker Thread #2 - which I'm guessing is my 2nd physical CPU -- which would be Core # 1 --- which would require tweaking of GTL (1/3), right?

My settings so far:
CPU 9.5x
FSB 443
FSB STRAP 266
RAM 1111 or 554Mhz in CPUZ

vCPU 1.35 BIOS, 1.316 CPUZ
vPLL 1.52
VTT AUTO
vDIMM 1.9
vNB 1.26

Before I tried to OC the CPU, I made sure my RAM and FSB were stable and ran Orthos for 3.5hrs +, spent about 2 or 3 days with the system (ripping DVD's, etc...) and it was fine. So I think the RAM and FSB are fine.