I play the game in OpenGL mode, but I've also noticed that W2000 likes to cache the hell out of this game. I have 2 different swap files set up at 256MB each, and after I play an hour or so the drive starts to crank away and get bogged down. Restarting the game puts performance back to normal, but that's a pain.
I posted a question about this problem in this group under "W2000 Caching Questions", but so far no one has a solution. My theory is that W2000 is just a resource hog, and it's going to use whatever it has to the max. Adding more RAM might help with W2000, and I think I might invest in another 128MB. Please let me know if you fix this problem.