Hi j -
I've got a very similar setup - P4C800D... the bios has an overclock feature that does all the calculations for you... you just specify a percentage (5, 10, 20 or 30)... I get 10% over with no problems, ran burn-in for hours... at 20% I get some system hangs... but, even at idle, with an X-SuperAlien with 6 fans and a Thermaltake orb cpu tower/fan, my cpu temp is in the low 30's - are you using the Bios' temperature detection? When I overclock and run burn-in (naturally heating that sucker up) it gets in to the high 40s... but this is normal I think. I am getting a waterchill watercooling system to see if I can get it up to3.4ghz... we'll see. Meanwhile, your cpu temp just seems way too low. That's why I am wondering how you are measuring it.