My problem is similar to two other posts concerning ATI cards and 12.04 LTS: Post1 & Post2. In my case I use a Dell Precision M4300 laptop which uses a NVidia Quadro FX 880M. Doing a lspci | grep VGA gave me this: 01:00.0 VGA compatible controller: NVIDIA Corporation GT216 [Quadro FX 880M] (rev a2) My workaround consists of logging in at the console and running sudo start lightdm which works perfectly but I am looking for a better workaround than this ?