I have the same problem, but I do not know what action causes the blockage. The only way I found and killed gnome-panel. Why I do ctrl + alt + F1, then once connected: sudo killall gnome-panel
Fresh install of 12.04 with gnome-session-callback / gnome-panel - no effects Gnome Force Quit applet on gnome-panel. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1006490 Title: Gnome Classic 12.04 panel applet “Force Quit” locks up system, hardware reboot to recover To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-panel/+bug/1006490/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs