do this for MOSFET cooling on TRUE: also try turn up p182's fan, see if your system have enough general air flow
Those are really extreme changes for MOSFET temp. One (possible) reason might be the heatspreader isn't on right. Give it a wiggle? Does it feel rigid? The thermal paste for it may have been applied poorly in the factory, all I can suggest is taking it (you'll need to remove the NB too) and re-applying thermal paste. This might not be easy though, as they look like they are held by pushpins, harder to work with than scews. I'd leave this as a last resort, if you can't find any other reasons.
Eh, the NB temp problem is kind of fixed now, I played the game today and it was just up to 50C, not a single degree more. I wonder what was going on yesterday. Thanks for the suggestions anyway.
Have you updated the BIOS on the P5Q? I recall reading that the latest BIOS had issues with temperature sensors? May be worth a trip to the Asus forums to do some research.
Yesterday I ordered a WLAN card (D-Link DWL-G510) and a fan to it. I thought about getting an Antec TriCool but they were out of stock so I got a Xilence RedWing 120. I looked for a fan with the specs of about the same as the TriCools have on medium and this was what I found. Code: CFM dB Antec TriCool 56 25 Xilence RedWing 60 21