I'm using
SOYO "SY-P4I865PE Plus DRAGON 2 V1.0" and the sensors are not working correctly.
BIOS is telling me one thing and Speedfan another. MBM5 went haywire...
I'm going to reinstall the heatsink (thermalright 947U* w/ Arctic Silver 5 and 92mm L1A @ 11V for safety - on a p4 2.8C**) - I suppose the paste could have been squeezed out. The Southbridge feels hot - pasting an extra heatsink on there couldn't hurt.
*I would have ordered one of the newer thermalrights had I not already had this one lying around.
**This is for my sister, and she insisted on an intel processor.
EDIT: Now that BellSouth DSL is working again, I've installed most of the lastest updates/drivers/etc. These P4s just zip right along!