After a seemingly innocent kernel update to 3.5.0-27 my nvidia drivers went crazy and stopped working. Should have been simple enough to fix, but somehow after a reinstall and reboot I was stuck at a black screen with a blinking cursor and my keyboard not working so I was unable to enter a tty. In case you find yourself in a problem like this, try the following which worked for me.
Reboot your machine and when grub pops up (hold shift) to boot into recovery mode. Select to open a root terminal when the recovery mode loads and do the following
Remove lightdm window manager and the current nvidia drivers
apt-get remove --purge lightdm nvidia-current
Keep in mind, that if you installed the nvidia drivers directly from their website, you need to download the same run file again and run it with —uninstall
After that, simply install lightdm and nvidia-current again
apt-get install lightdm nvidia-current
And then run
service lightdm start
This method worked for me, but countless others didn’t, so hopefully it works for you.