In one of the virtual terminals, try "killall X". See if that gets rid of the blank desktop and turns it into a command line. If that doesn't work, try "killall xorg" and "killall Xorg".
If it restarts itself, try running "killall gdm" before trying the above.
Then, run "xinit $(which xterm)". If everything's fine, it should come up with the gray screen but with a terminal window with no border.
Try it and report back.
Last edited by MTK358; 11-25-2010 at 05:07 PM.