Failed to parse existing X config file ‘/etc/X11/xorg.conf’
If you are trying to save your xorg.conf file after changing settings in the nvidia-settings app you may need to first replace it with
sudo nvidia-xconfig
This will back it up and then recreate it. Seems a fresh install of Karmic Koala 9.10 doesn’t create a valid xorg.conf or it can’t parse it. Whatever the case, that’s the fix.
Then you can
sudo nvidia-settings
To change and save your settings.