I had this problem today, If I start Google Chrome or Chromium it logs me out of X.
uname -a gives
Linux garethf-System-Product-Name 3.5.0-19-generic #30-Ubuntu SMP Tue Nov 13 17:48:01 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
and I'm using propriety NVIDIA-Linux-x86_64-310.19
The Xorg.0.log showed a NULL deref in /usr/bin/Xorg. I can only guess that some of the kernel headers must have updated yesterday as it was working fine, but not enough for the nVidia driver not to work. I fixed it by rebuilding the propriety nVidia drivers. All seems to be working fine now, might be related to this so posting just in case it helps anyone.
I had this problem today, If I start Google Chrome or Chromium it logs me out of X.
uname -a gives
Linux garethf- System- Product- Name 3.5.0-19-generic #30-Ubuntu SMP Tue Nov 13 17:48:01 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
and I'm using propriety NVIDIA- Linux-x86_ 64-310. 19
The Xorg.0.log showed a NULL deref in /usr/bin/Xorg. I can only guess that some of the kernel headers must have updated yesterday as it was working fine, but not enough for the nVidia driver not to work. I fixed it by rebuilding the propriety nVidia drivers. All seems to be working fine now, might be related to this so posting just in case it helps anyone.