I doubt this is the problem... but it is worth trying...

Does the motherboard have a CMOS battery? If so, check it... you can usually pick them up for less than 10-15 US dollars..



But I highly doubt that it is the cause.

I would check to see if you could try a new motherboard BIOS update or something like that.

Also if you have another PIII CPU you could try in the machine would certainly rule out another possible problem.