After applying the most recent upgrades to Fedora 11 installation, my Gnome desktop became corrupted. The panel at the bottom of the screen is entirely missing, the strip at the top of the screen is only a few pixels wide and has no icons or "clickables", and the window decorations (open/close buttons) are missing. The suspect package was Gnome power manager. Right after the upgrade it reported a configuration error, which I did not save.

I initially tried reinstalling the desktop theme. I have uninstalled the power manager rpm, and removed all of Gnome's configuration-related directories (.gnome, .gnome2, .gconf, .gconfd, and .metacity). I tried creating a new user; that desktop is corrupt as well, so I then went into root's directory and removed the desktop directories from there, thinking that maybe Gnome used them as a skeleton. After seeing no improvement, I reinstalled the gnome desktop environment as a group.

The KDE desktop works ok, but Gnome still does not. I'd appreciate any advice on getting it fixed.

First try with creating a new user. Does gnome work OK for him? You should do that to check if the defaults are sane. If it does work with no problems, then login using a terminal (while not running gnome) and:
Try logging to gnome after that. Everything should be set to default.

If it doesn't work for your new user, then there's something wrong with the packages you upgraded.

My desktop is fixed; unfortunately I can't tell you exactly what did it.

Creating a new user resulted in a mangled desktop.

Deleting the .config files did not fix either my login or the new login.

I downgraded the Gnome desktop RPM packages - did a yum update group to find out what packages were involved. This didn't help.

I began recreating the desktop from scratch. After logging out and logging back in to the user account, almost all of the defaults returned. The only thing missing is the min/max/close buttons at the upper left of the window. I tried unsuccesfully to restore them through the theme manager. I can live with the system as-is.

It seems like some settings were mangled, and recreating the desktop brought it back close enough to sanity that Gnome could fix itself the rest of the way.