Don't forget to let people know what your memory setup is. This is often more important than your Video card/Sound Card setup.
Apparently, I had similar problems when I had 3 PC66 rated 32Meg sims. So I was taking up 3 sim slots for 96 megs. Not all of the memory was rated the same speed (Doh!). Well, many applications don't have problems with this. Unreal, however, had big problems with this. I was getting everything from dropping out of the game. To all sorts of actor/GPF errors. To a real strange case whih locked all USER input (no keyboard or mouse input registered), but allowed my computer to run fine, otherwise.
To make a long story short. I got rid of that ram and replaced it with 64 megs of PC100. Plan to get another PC100 64 meg sim of the exact same type and speed. Well, UT runs perfectly now with no bugs whatsoever. The random or strange errors are basically caused by Page Faults. Writing into memory that doesn't belong, or getting trapped into writing to wrong addresses. Win 98 is partially to blame, but this warning to let you know, be careful of that RAM. It's an issue that people don't speak enough about.
By the way, I gave UT the overnight test. 8+ hours of straight running, no crashes, no problems, no noticible memory leaks. From Single Player/ to Multiplayer/ to Chat/ etc. All due to getting my Memory straight. That night, I think UT ran for over 10 hours, but I had come out and back in. The 8+ hours was in one run, without exiting the program. Though I did task switch to my desktop during that time used my web browser, and back.
-- Akaimizu