Maybe this is linked to bug https://launchpad.net/ubuntu/+source/xserver-xorg-video-mga/+bug/58721
It did not occure again since installing the mga driver version 1.4.4 mentioned there -- [edgy regression] random X server crashes https://launchpad.net/bugs/74479 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
