Have you tried the latest Catalyst? (13-8 Beta2)
Here's how I would do it..
Start by making sure everything's purged (some of these commands will probably fail, but don't worry about it and keep going)
sudo sh /usr/share/ati/fglrx-uninstall.sh
sudo apt-get remove --purge fglrx*
sudo mv /etc/X11/xorg.conf /etc/X11/xorg.conf.backup
sudo rm -rf /etc/ati
If you're using the x86_64 architecture (64 bit):
sudo apt-get install build-essential cdbs dh-make dkms execstack dh-modaliases linux-headers-generic fakeroot libqtgui4 unzip
sudo apt-get install lib32gcc1
mkdir catalyst13.8beta && cd catalyst13.8beta
chmod +x amd-catalyst-13.8-beta2-linux-x86.x86_64.run
sudo ./amd-catalyst-13.8-beta2-linux-x86.x86_64.run --buildpkg Ubuntu/precise
sudo dpkg -i fglrx*.deb
sudo amdconfig --initial -f
Be more specific. Does the error occur before the login screen or after you log in? Can you get to a terminal (Ctrl+Alt+F1)?
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