I spent about 3 hours too. I was completely baffeled that downgrading nvidia (from aptitude which is a pain compared to synaptic) didn't solve the problem. Worse, ppa-purge also didn't change anything (downgrading everything to the original state right?).
I tried modprobe nvidia which completes without any message but doesn't load nvidia. And modprobe nouveau also didn't load (with error messages). Desperately, I removed all nvidia stuff (after the ppa-purge) and managed to boot into kde with now the nouveau driver. Then purged all removed packages and installed nvidia again with jockey. Good to know bumblebee.conf is causing the problem. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to nvidia-graphics-drivers-331 in Ubuntu. https://bugs.launchpad.net/bugs/1265570 Title: nvidia-331 update installs bumblebee [xorg-edgers] Status in “nvidia-graphics-drivers-331” package in Ubuntu: Confirmed Bug description: Hi xorg-edgers team, I just got the nvidia-331 update, from nvidia-319, but the update installs bumblebee, however when bumblebee is installed it blacklists the nvidia kernel modules. Which bumblebee is suppossed to do but it breaks xorg if you aren't running an optimus based GPU. Uninstalling bumblebee does not remove the /etc/modprobe.d/bumblebee.conf config file and as such the driver is still blacklisted until you either modify the file to not black list the nvidia-331 module or remove bumblebee.conf. I have an nvidia 560 GTX video card. Tareeq To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/nvidia-graphics-drivers-331/+bug/1265570/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp