Comment 43 for bug 561049

There is nothing obvious in the log files to show what the cause of the issue is.

Next time it occurs can you check of the device nodes exist? Here's an example of what you should expect to see:

ls -l /dev/nvidia*
crw-rw-rw- 1 root root 195, 0 2010-04-19 09:36 /dev/nvidia0
crw-rw-rw- 1 root root 195, 255 2010-04-19 09:36 /dev/nvidiactl