I have the same problem as previously reported by Dave (see here).
Unfortunately my desktop is not turning back 80% of the time like Dave's. By 80% I mean that, from time to time, when I restart the computer, I get the desktop back but most of the time nothing. By nothing I mean my panel, etc, seem to be in place but I don't see My computer, trash, etc. icons and I have no wallpaper. Nautilus does not launch if i try to. I have not been able to see any error messages.
I am running FC3 standard with all the up2date applied and no SELinux. This is a clean scratch FC3 install. During 2 weeks i did not have that problem. It appeared a couple of days ago and I have been unable to find a solution.
Bertrand