Comment 63 for bug 286424

Ubuntu 9.10 (karmic)
Kernel Linux 2.6.31-12-generic
6-10-2009 at 21:40 (dutch time) completely up to date

same bug
solved it by using sugjested commands.

user@desktop:~$ sudo nvidia-xconfig
[sudo] password for user:

Using X configuration file: "/etc/X11/xorg.conf".

VALIDATION ERROR: Data incomplete in file /etc/X11/xorg.conf.
                  Undefined Device "(null)" referenced by Screen "Default
                  Screen".

Backed up file '/etc/X11/xorg.conf' as '/etc/X11/xorg.conf.backup'
New X configuration file written to '/etc/X11/xorg.conf'

user@desktop:~$ gksudo nvidia-settings

Hope this helps solving the problem.