Comment 20 for bug 825777

You can install Ubuntu 11.10 using the alternate install CD.
When you first boot, you have select the grub entry (press shift while booting if it doesn't show) and press 'e', then add the word 'nomodeset' to the end of line that has the kernel arguments. The graphical display manager will fail to start, but you can ctrl+alt+f1 to drop to a tty. Login and: sudo apt-get install fglrx && sudo reboot
It worked for me, but I hope it gets fixed by 12.04