Comment 4 for bug 728923

Seems slightly related to:

https://bugs.freedesktop.org/show_bug.cgi?id=35502

For the worst affected (like me) who can't even boot into ubuntu 11.04 without the freeze loop, do the following:

After booting off the usb/cd drive, at the purple screen splash hit enter, then hit F6, and select radeon.modeset=0 and boot like normal, you should end up on the Ubuntu Classic Desktop, which you can then install Ubuntu with, and proceed to install the proprietary drivers to get the unity goodness.