gdm login busted

[Jim Duda <jim duda tzo com>]

I recently upgraded from fc7 to fc8, about a week ago.

Today, my gdm login is busted.  After I enter my user name and password, 
gdm just hangs, and never starts up the desktop.

I have to boot the computer into init 3, login to a shell, then run startx.

I do know what I could have done to break this.

I no longer have a "login screen" configuration entry in 
system->administration, if that means anything to anyone.

I uninstalled and reinstalled gdm, no luck.

Same issue with any login, including root.

Any ideas?

Jim