xlock stops running

[Sorin CONSTANTINESCU]

Soon after upgrading from Ubuntu 11.10 to 12.04, I noticed that my screensaver was sometimes not running, leaving my system not password protected.

I switched from xscreensaver to xlock and the issue just keeps repeating. I don't have any clue on how to troubleshoot this, but I did see that auth.log doesn't show some Stop entries for the times it "crashes":

auth.log.1:Jul 6 16:30:46 consta-MacPro xlock[5514]: Start: constantinescu, constantinescu, :0.0
auth.log.1:Jul 6 16:57:13 consta-MacPro xlock[5514]: Stop: constantinescu, constantinescu, :0.0, 26m 27s
auth.log.1:Jul 6 17:12:42 consta-MacPro xlock[13406]: Start: constantinescu, constantinescu, :0.0

The latest occurrence was this morning. As you can see, PID13406 started on Friday, but there's no entry for it being Stopped.

root@consta-MacPro:/var/log# date
Mon Jul 9 10:00:30 CEST 2012
root@consta-MacPro:/var/log#

Could anyone suggest what I could do to troubleshoot this further? It's getting really annoying!

Thanks!

[Sorin CONSTANTINESCU (consta)]

I think my issue is similar to Bug #493695 . I also have two monitors.