Upgraded from 12.04-->12.10. I'm able to use Unity and Cinnamon, but when I try to run Gnome Shell I never fully get the desktop. One of my startup apps appears and it's missing its Window decoration. I can't get the Dash or to apps. I'm able to go into the Classic session.
I've tried uninstalling and reinstalling the Shell to no avail.
I'd previously had the Gnome-team PPA and Rictoz testing, but have removed and purged those.
How do I troubleshoot this?