Comment 14 for bug 138933

Just want to add to this:

I triggered this bug by installing nvidia-glx-new, which didn't work for a specific card (too old), and then removing that and installing nvidia-glx. It looks like the hidden file /lib/linux-restricted-modules/.nvidia* caused the old 7XXX series kernel driver to be used instead of the 9XXX series after nvidia-glx-new was removed.

The fix is to just make the removal scripts for nvidia-glx-new make sure to remove the hidden file @ /lib/linux-restricted-modules/.nvidia*