Since the last update of ubuntu 12.04, the system won't boot into gui anymore. It states that it was unable to load the graphics drivers and gives me 4 options, these are:

• run in low graphics mode for 1 session
• reconfigure graphics
• troubleshoot the error
• exit to console login

whichever option I choose, it doesn't solve anything. For instance, when i choose to reconfigure graphics and then switch to vesa drivers, the screen goes back to the option list.

So i configured xorg.conf to vesa myself, and i see in the update history that ubuntu updated xserver-xorg-core and xserver-common whereas i blocked these updates in synaptic since i'm aware that updating these files caused troubles with my particular video card (radeon hd6800). So my solution is probably to revert these files to the older (working) versions. How can I do this please (in particular xserver-xorg-core since i think this is the main cause of my problem).

thanks!

output of ls /etc/X11

-app-defaults
xorg.conf
Xreset
-cursors
xorg.conf-backup-120529144709
Xreset.d
-default-display-manager
xorg.conf.fglrx-0
-Xresources
-fonts
xorg.conf.fglrx-1
Xsession
-rgb.txt
xorg.conf.fglrx-2
Xsession.d -X
xorg.conf.original-0
-Xsession.options
-xinit
xorg.conf.original-1
-Xwrapper.config
-xkb
xorg.conf.vesa

Output of sudo aptitude show xserver-xorg-core | grep Versie (read: Version in Flemish)

Versie: 2:1.11.4-0ubuntu10.2