I just built that system, stuff is clean. Could be the video card - it's brand new, but it's already a replacement for another brand new card of the same type and from the same manufacturer that broke after a week or two (Powercolor Radeon 9800 pro). And the sales guy at the computer store told me that they had a lot of problems with Powercolor hardware.
On the other side did I play D2X-XL for hours yesterday w/o problems.
I was browsing the Descentbb.net when the crash occured. I was scrolling up quickly - bang.
I am using YaST to launch the updater, but I don't know what tool does the actual updating.
Interestingly enough I can completely freeze my Linux box by launching a fully compiler-optimized (-O2 or -O3) version of D2X-XL and simply quitting it right away after the main menu has appeared. It will crash in some SDL shutdown code (very likely video related stuff). Mouse will still move, but I cannot switch windows or enable the text console (not a terminal) by pressing Shift+Ctrl+F1 or Shift+Ctrl+BkSp or soft reboot. I have to press the reset button. If I have the compiler add debug info (even if still using -O2), everything works. This does not look like a hardware problem.
OpenSUSE 10.1 for AMD 64.