XP clock losing time

[Ryan_Fpv]

When I'm playing Assassins Creed my computer clock loses 5-10 minutes of time after a few hours of play. I doubt that it's the cmos since the clock is correct when I turn the computer on and it has never lost time just running idle.
Is it because Assassins Creed is draining the computer so much that it causes it to lose time?

 

[Jiffyman]

A quick search on Google brought up this.

http://support.microsoft.com/kb/189706

and this

http://pcworld.about.com/news/Dec282001id77304.htm

Hope this helps. Sounds like a fairly common issue. That's why we have NTP servers.