I'm on the latest 14.04 with
nvidia-331 drivers installed. Everything runs smoothly just when I try to switch user I get a black screen. Suspend and logout works with no problems.
Somehow I managed to make it work ones but after restart it was broken again and I'm not able to repeat the steps I made.
Seems it's an
nvidia driver or
lightdm problem since I can still connect by ssh even with black screen.