I recently upgraded from F12 to F13 using preupgrade.  Everything seemed to go well, except for one problem I think I've traced to the screensaver. 

When I lock the screen now at the console, I get logged  out of my session after a short period of time (a few minutes) .  My first thought was that maybe one of the screensavers was bad, so I went to change that one I was using, but as soon as I selected another one (not even having to hit preview), I get logged out, although it does seem the selection is changed.  I tried unlocking immediately, and it works.  If I unlock the screen after a couple of minutes, but before the unwanted logout, the screen just goes black, and I can't get in. The system is still running, though, since I can get in via SSH.

I do see in /var/log/messages that is looks like Xorg is coredumping, but I don't see anything to indicate why.

Has anyone else had this trouble?