Removing OpenGL packages that seem to have corrumped my display drivers
 

I downloaded Googleearth to my ubuntu 9,04/64 installation. When i started Ge i only got an flickering image on the screen.
I then tried to install some opengl-driver packages to correct the problem. It didnt seem to make any difference, but on the next reboot I'v lost connection with my display.
Hardware:
ASUS P5Q Mobo
4GB ram
3GHz DualCore
Acer Wide screen running 1920x1080
and an old Ati X800 graphics-card

It's probably no hardware problem, since the computer is booting nice into the other installations.

You may need to just reconfigure X and start the config again. Use the terminal directly (ctrl+alt+f1 most likely), then login and run the following:

sudo /etc/init.d/gdm stop (or kdm stop if you are using kubuntu)
sudo cp /etc/X11/xorg.conf /etc/X11/xorg.conf.backup
sudo dpkg-reconfigure xserver-xorg

Choose either VESA or ATI driver - VESA will be the lowest common denominator. It should always work - and ATI will give you the default open source ATI driver.

From: http://ubuntuforums.org/showthread.php?t=690760

It's pretty straightforward to reconfigure X - most likely one of the packages that you installed just conflicted with something.