the shutdown on mine was 95c stock yeah right i dropped that down to about 80c.
and there aint no way i'm puttin more than 1.65v to my cpu. for one thing, from what i know tinkering with mine (which i do A LOT), any voltage over about 1.525 doesn't yield any kind of viable result, ie. you have no reason to run it at that high of a voltage, you're not going to clock any higher, and it's stable at way less voltage. your just generating heat. bunches of it.
i can get up to 2.85 on 1.5 volts, and "i'm givin her all she's got, captain". it's not going any higher, period.
if someone can show me results of their x2 4200 rig running at a higher clock then 2850mhz, i'd sure like to see it so i can interrogate you.
p.s. thats on socket am2. the world record is 3.6 somethin with a s939 x2 4200+