try load "glx" module in /etc/X11/xorg.conf:
Section "Module"
Load "glx"
Load "extmod"
Load "xtrap"
Load "record"
Load "dbe"
Load "dri"
Load "freetype"
Load "type1"
EndSection
glx is already loaded.
Section "Module"
Load "vnc"
Load "dbe"
Load "extmod"
Load "record"
Load "xtrap"
Load "glx"
Load "dri"
Load "freetype"
Load "type1"
EndSection
But I think it is indifferent, because I've just bought a new graphics card (because of my new flat screen). Hopefully, the nVidia driver supports it. My old one (Riva TNT2) is not longer supported (it actually was supported a few years ago, but nVidia only has these all-in-one drivers. I just can't find the old one).
Nico Schümann