Comment 1 for bug 292103

I don't think this is the same bug as stated as the screen works for kubuntu splash screen both start-up and shutdown and all the same I have found a fix and solved the problem and now Itrepid is working brilliantly :). Ok so this is what i did:

1.Used recovery mode option and logged in a root user
2. run apt-get remove --purge xserver-xorg-video-ati xserver-xorg-video-radeon
3. use the command 'exit' to get back to recovery options then run the xfix (xserver recover tool) (I'm not sure whether this acctually achieves anything but it worked :) )
4. Restart Kubuntu will run using vesa drivers and works fine
5. install fglrx using jockey

From doing this i was curious what the problem was so reinstalled the xserver-xorg-video-ati package and same problem occured so it appears to be a problem with those drivers and the Sapphire 3850HD AGP card but fglrx works just fine with it so try as above.