Comment 9 for bug 92856

You driver kernel module couldn't be loaded.

Unfortunately I still don't see the reason for this, so I have to assume that the deinstallation/reinstallation left you with some files/modules or symbolic links which are messing up your configuration (note that the proprietary drivers you have installed and uninstalled where not packaged in accordance to the ubuntu standards).

The only suggestion I can give you is to check that all the relevant files are where they are supposed to be (for instance by checking the packaging information) and that there are no leftovers from the previous installation.