Uninstalling gnome-screensaver solves the issue. Obviously you lose the screensaving functionality, but you can switch users with the fast user switch applet. When password is needed GDM asks for it, not the gnome- screensaver locked screen.
** Changed in: gnome-screensaver (Ubuntu) Status: New => Confirmed -- Can't unlock screen when using a password-less account https://bugs.launchpad.net/bugs/589299 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs