>I had similar problems with the Diamond Viper Card which came in my "top of the line" Micron Pentium just two months ago. However, I called Diamond and got new drivers which completely eliminated the crashes. I'm not an expert on hardware (or anything ese for that matter!) however the problem is in a chip set which is common to many video cards. Keep trying on the Driver upgrade!
The best bet for the Diamond card, and all other cards using the nVidia chipset, is probably nVidia's Reference driver for the TNT chipset. I've been very happy with it (tons better than the original Diamond driver) and extremely stable. The same driver works with the STB4000 and the Asus 4300.