Comment 3 for bug 1265570

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.