TW updated to Gnome 3.8.
It didn’t work for me. But after further updates today, it now works.
I installed gnome-shell-classic (I hope I got that name right). And I then logged into Gnome classic.
That doesn’t work either. If I switch to GDM, it then works. But it does not work from the KDM menu. Presumably there’s something broken in the KDM menu for Gnome classic.
(Not sure whether this should be reported as a bug. Or maybe Greg watches posts here and can fix it without a bug report).