Forget most of my previous message. It now appears to be the case that I have crashes in combination with certain kernel: 3.2.0-3-amd64 CRASH 3.7-trunk-amd64 no problem 3.12-1-amd64 CRASH 3.13-1-amd64 CRASH As soon as I have an Xorg log with the error, I will post it here.