When launching, nvidia-settings it just hangs

I've just upgraded to 11.10 and now nvidia-settings won't launch. If I run it from the command line (as me or as root) it just hangs.

How can I debug this?

Try to completely remove your nvidia drivers from your system:

sudo apt-get purge nvidia*

Remove your xorg.conf

sudo rm /etc/X11/xorg.conf

Reinstall xorg completely

sudo apt-get install --reinstall xserver-xorg-core libgl1-mesa-glx:i386 libgl1-mesa-dri:i386 libgl1-mesa-glx:amd64 libgl1-mesa-dri:amd64

Re-configure Xorg

sudo dpkg-reconfigure xserver-xorg

Reboot

sudo reboot

You should be greeted with lightdm, this will default everything x the same way a fresh install would. After that you can try installing nvidia from the "Additional Drivers" application.