Blank Screen after login on Fedora 19

[Craig Lanning]

I have a laptop in a dock with an external monitor.  In Fedora 18, I
configured it use the external monitor as the primary display and to
turn the laptop screen off.

The machine in question has the following configuration:

HP EliteBook 8560p
Intel(R) Core(TM) i7-2620M CPU @ 2.70GHz
8GB RAM
ATI Radeon 6400M
Docking Station with 1920x1080 monitor (connected via DVI) and wired
network.
Fedora 19 64-bit

If I create a new user, I can log into the new user just fine.  I see
both monitors with the laptop screen being primary.  If I change it so
that the external monitor is primary and the laptop screen is off, I can
reboot and login just fine.  After I customize the desktop a bit, when I
reboot and login, I get a blank screen with a mouse pointer, but it
never goes any further.

I've seen comments about changing the display manager to either kdm or
lightdm, but neither of those helped. It still behaved the same.  I even
found a comment about logging in to a text system (no display manager)
and using 'startx' to start the desktop.  I tried that, but it still
behaved the same.

Is there some way I can regain control of the user?

Is there a way I can reactivate the laptop screen without using the
Display applet in the gnome-control-center?

Craig