On Mon, 30 Nov 2009, Brian D. Ropers-Huilman wrote:

> Mike, go to one of the TTYs (CTRL-ALT-F6), login, and try restarting the GDM:
>
> sudo /etc/init.d/gdm stop
>
> then
>
> sudo /etc/init.d/gdm start
>
> Then switch back to the GUI console (CTRL-ALT-F7) and see if the GDM 
> will accept an ID after restarting. It might automatically take you to 
> the GDM after it restarts, I can't remember.


Thanks for trying, but that did not go well!  There definitely is 
something quite abnormal here, so your idea might usually work, but not 
this time.  Stopping gdm went OK, but when I entered the start command, 
the screen went black, and that was it -- I could find no way to get 
anything back.  The machine was still on but I couldn't ping it or connect 
in any way.  The ctrl-alt-F? combinations did nothing.  It was totally 
unresponsive, so I rebooted it.  One funny thing was that the black screen 
did not mean that there was no video -- the monitor never went into 
power-saving mode.

Rebooting did not solve my problem.  When Gnome comes up to the login 
screen there is something very pathological going on.  The login box in 
the middle of the screen is flashing on and off very rapidly (3-4 times 
per second).  It always shows the name of the computer and and about once 
per second it flashes "unable to authenticate user" at the bottom of the 
box.  I tried hitting ctrl-c and a couple of other things, but it did 
nothing.  I can return to ctrl-alt-F7 and enter commands there.  I also 
can start vnc and I'm using that now from my netbook, but I don't know how 
to make the vnc client work on the desktop when Gnome is down.

At least now I don't have to worry about losing any work so I'll just 
reboot repeatedly, changing various things, and I'll see what happens. 
Any suggestions?

Mike