I had the same problem until I upgraded my glibc. See: http://www.nvnews.net/vbulletin/show...=rh9+quake+iii
I have a regular Geforce3
I get past the 'couldn't start X display' for Quake. Couple things to note:
On 4349, I can get to where it shows the first frame of particular level. Then it freezes.
On 4363, same thing happens, but my Intellimouse doesn't work at all anywhere in Quake now. Noticed this time, however, that at lower resolutions (800x600) than 1600x1200, levels are playable, but still no mouse.