Using Debian Testing or Unstable, or a frequently upgraded version of Ubuntu,
when doing an apt-get update && apt-get upgrade often will install a slightly
newer version of xserver-xorg-code, and this will break the NVIDIA
proprietary drivers, if you, like me, prefer to install them using the official
NVIDIA installer. When this happens, at your next reboot, or next time you
start X, this will crash.
Follow this instructions and you won’t need to reinstall the NVIDIA driver from
scratch each time. First of all, stop your login manager (gdm assumed here):
/etc/init.d/gdm stop
Then move to:
cd /usr/lib/xorg/modules/extensions
Normally it should look like this:
total 956K 1 root root 19K 2007-01-09 21:13 libdbe.so 1 root root 34K 2007-01-09 21:13 libdri.so 1 root root 145K 2007-01-09 21:13 libextmod.so 1 root root 18 2007-01-15 20:42 libglx.so->libglx.so.1.0.9742 1 root root 676K 2007-01-15 20:42 libglx.so.1.0.9742 1 root root 28K 2007-01-09 21:13 librecord.so 1 root root 38K 2007-01-09 21:13 libxtrap.so
Notice the symbolic link from libglx.so to libglx.so.1.0.9742. In your
case, instead, the installation of a newer xserver-xorg-core overwrote the
libglx.so with the normal one provided by the X Server. What you have to do
is simply restore the previous situation. Remove the libglx.so file:
sudo rm libglx.so
And make the symbolic link again:
sudo ln -s libglx.so.1.0.9746 libglx.so
Of course the version number, in my case 1.0.9746 may be different in your
case. Now you can simply start the gdm login manager again:
sudo /etc/init.d/gdm start
Everything should be working again.
Thanks to http://osrevolution.wordpress.com/ for this.