ABIT NF7-S CMOS temperature is -61.99

I have two Abit NF7-S MB computers. One with an Athlon XP3000+ CPU (166 MHz
x 13) and the other with an Athlon XP2600+ CPU (166 x 11.5). Both have 2
gigs of memory. The CMOS readings of PC Health status are normal EXCEPT for
the -5V value which is approximately -61.99 (it changes a little) on both
systems.

The XP3000 system power cuts off suddenly when using ram intensive programs
like Cool Edit Pro 2.1 or Canopus Pro. The XP2600 system is more stable and
requires heavier application loads before it's power cuts off.

I have the "Shut down when CPU fails" enabled. I'm afraid to disable it but
it seems like this might be causing the shutdowns.

I know that the problem is not with the power supply or with the Ram chips.

Any suggestions would be most appreciated. Thanks.

Foodini