Overclocking T5600 in 3680

This thread is a carry over from the C2D upgrades on the aspires with stock celerons.

A quick catch up: put in a C2D T5600 (ES) in my 3680-2682.
In stock form: Celeron [email protected], FSB 533, 80gb HD, 512mb of 533 ram.
Now: C2D T5600 (ES) @1.833, FSB 667, 500gb HD, 2gb of 667 ram.
My windows index score has gone from 2.1 to 3.0.

I'll try a screenshot of my first real attempt. overclocked frontside bus to run my ram nearer its rating of 667 (3680 would normally run mem at 533) and then lowered multiplier so cpu overclock wasn't too high (2066 as opposed to 2200ish). I tried for a bus of 204 but looks like it was more like 186 (based on 2066 with 11x multiplier)? I also put voltages to near the t5600s oem settings (I think) with range of 1.036v - 1.363v.
I ran Orthos with small ffts and Prime95 with combo test, side-by-side.
After 24 mins approx my cpu's tmax had been 87C and it closed my user session bringing me to the log in screen. I immediately logged back in and took this screenshot. That's all I've done so far ( or should I say "too far")!
I'll end up going the undervolting route, but have a question about the failed test. would you guess that the cpu failed for lack of voltage or maybe just the gpu hitting the wall? It seemed like when I logged back in the tests were still running.
Thanks