Strange power down issue

[ControlD]

I have a strange issue with my main home computer that has me scratching my head a bit. The system in question is as follows:

AMD XP2800+
MSI K7N2D-L motherboard
Antec Tru-Blue 430
EVGA GeForce 6800
Sounblaster Audigy
(2X) hard drives
(2X) optical drives

This system has been running just fine for almost three years now, but just recently when I shut the computer down, after the power shuts off the computer does this weird on-off-on-off-on-off (maybe 10-12 times) at a frequency of about 1 second or so. Everything powers on and off very briefly several times until the power finally shuts off. I would be tempted to say this is a power supply problem, but I think I would be seeing more problems than this.

Has anyone ever seen something like this before?

Thanks in advance,

Dave

 

[KGB]

Dave,

Try clearing the CMOS.