Customer's Windows ME system will start to lose time after being on for a few hours.

Checked motherboard battery and it appears fine at 3.1 volts (2032 coin cell).

Turned off power management in BIOS per Microsoft Knowledge base article. No affect on problem.

If he reboots the ME clock resets to the proper time (so I think that means the bios clock is keeping time properly).

What could cause the Windows clock to start to lose time? Customer claims it loses significantly, not just a few minutes, and gets worse as time passes. Other claim made is that the cursor starts to display erratically.

Did a full virus check with recent downloaded virus check data and system appears clean.

System is Athlon 800 on an Aus A7v mb.