The logs don't show anything unexpected, but it does appear to have the same symptoms as in bug 851345. Doug, can you check if the lightdm process is running after the problem occurs and if dmesg shows it has crashed?
The logs don't show anything unexpected, but it does appear to have the same symptoms as in bug 851345. Doug, can you check if the lightdm process is running after the problem occurs and if dmesg shows it has crashed?