Any attempt to run any program that uses GLX causes signal 11, causing immediate X shutdown. With TV-OUT enabled, this hangs the system, forcing cold-reboot. This aside, I have disabled TV-OUT in order to diagnose this problem.
glxgears is the test program I have been using. I've read through the README file and followed hints and instructions to repair this problem to the best of my ability, but I've run out of ideas. I'm not going to prejudice anything by posting my own theories - I've attached a .zip file containing just about everything I can think of, including log files, directory contents, and so on.
Distribution: Slackware 9.1
X related: Dropline GNOME 2.6.0
XOrg 6.7.0 Gnome 2.6.0
Card chipset: GeForce 4 Ti4200 128M memory
Nvidia driver: 5336
Contents of nvidiabug.zip:
cdrradar@aribeth:~/nvidiabug$ zip nvidiabug *
adding: XF86Config.single.nvidia (deflated 68%)
adding: Xorg.0.log (deflated 79%)
adding: console.perms (deflated 64%)
adding: glxgears.ldd (deflated 59%)
adding: ls-l (deflated 79%)
adding: xpdyinfo.out (deflated 90%)
Any additional information that's needed, please ask.