He's using the Intel 810E Integrated graphics decelerator, which also means
he probably doesn't have an AGP port available for most modern video cards. I recently pulled out an old 440GX dual processor mobo for use at work and had to get a GeForce 440MX PCI card because the AGP port was the 1.0 variety and won't handle the lower voltages of the newer cards.
Anyways, the Intel 810E video card is a real turd. I had it on my Dell at work and that is why I brought in my own PC built from leftover parts from upgrades over the years (With the exception of the 440MX card since I needed a PCI solution). I tried to install MOH and Spearhead and they wouldn't run on that card. I would suggest investigating whether you have an AGP slot for a dedicated video card and if not, look into PCI solutions. The I810e video card does not support many of the more advanced features of modern video cards. It is really for business/web use rather than gaming. I wouldn't normally recommen a GeForce 4 MX card, but if you need PCI that or possibly ATI is the way to go as ATI has not forsaken the PCI market.
You may try upgrading the I810 drivers from Intel's website as well.
http://downloadfinder2.intel.com/script ... in9x67.zip
That is the latest driver for your card.
Another problem may be corruted texture files since it is only occuring on certain maps, which will require a re-install, but current drivers are almost never a bad thing either.