Q3 problem

[foodog]

This isn't a high priority, but it bugs me.
I have RH 8.0 loaded on a P4 1.6 with a Radeon 7500 and 512MB RAM, using
KDE.  It'll start, usually with sound, and run great for about 1 minute
- then the display locks up so badly I have to reboot to recover.  
It initially complained that it wanted libGL.so, which is nowhere to be
found.  I made a link to libGL.so.1 and also tried libGL.so.1.2, either
of which seem to appease it.  I can still ssh in when it locks up, but I
haven't found anything short of a reboot that'll bring the video and
keyboard back.
Any suggestions on how to debug this?  The box doesn't have problems
with any other apps that I've noticed.
A couple of things I've tried from the Linux Gamers FAQ are starting it
with the commandline for no sound, and I made sure that KDE wasn't using
antialiased fonts.
Any suggestions appreciated, thanks :-)
Steve