Fang,
I have been having similar problems only on games with LOTS of units.
My setup is about the same but PIII with 128MB RAM. Same Video card.
I have WIN2K as well.
In my experience, after playing the game for about 30 minutes, the helmets of the soldiers, and the wheels of vehicles turn WHITE, then in about 2 minutes later the game crashes...
When I relaunch, the game things that the CD is not present and I have to re-boot to allow me to restart CM.
Anybody else seen this?
dk