I've used the latest proprietary nVidia drivers (313) when an update came and broke my desktop - initially it switched to some other drivers than proprietary (my second monitor wasn't used with it), then I switched it back to proprietary (313) and got low-resolution desktop labeled as laptop resolution. Then I managed to install stable nVidia drivers (310) and got it run again in proper resolution, but from that time I can't use any KDE applications. It just crash the X server upon launching an KDE application, turn my screens black and after a while it shows up Ubuntu login page.
I've tried apt-get clean, autoclean, correction of dependencies, etc., also I reinstalled the affected applications - nothing solved the problem.
I upgraded my system a while ago from 12.10 to 13.04 and I have set additional software source "http://ppa.launchpad.net/kubuntu-ppa/backports/ubuntu" because of the latest version of Kate editor. Everything is updated.
Does anybody experienced that kind of behavior and found a solution? Thank you for any kind of information!
Have a nice day