Yesterday I upgraded from 10.10 to 11.04, everything seemed to go okay until immediately after login: the desktop goes into a "corrupted" looking state (similar to having too high resolution set). I can see some kind of movement by moving the mouse around/right clicking, and can enter text terminals via ctrl + alt + f1

It does this in both plain "Ubuntu" and "Ubuntu Classic", and only seems to login/startup properly with Ubuntu Classic (No Effects).

I have checked my video card (Radeon X600) and run the unity support test which passes with all "yes" results (Unity supported: yes):

/usr/lib/nux/unity_support_test -p

I have tried re-installing my Ubuntu desktop:

rm -rf .gnome .gnome2 .gconf .gconfd .metacity
sudo apt-get remove ubuntu-desktop
sudo apt-get install ubuntu-desktop

With no success.

I can workaround for now with Classic (No Effects), but I'd really like to find the root problem. Any suggestions on what else to try would be appreciated!