Same thing happened to me. Was changing icon themes when it crashed. All panels disappeared and had to do Ctrl+ Alt + Backspace to get out and restart session. Xfce wont load again.
** Attachment added: "Crash File" http://librarian.launchpad.net/4842417/_usr_bin_xfce4-panel.1000.crash -- xfce4 panel crashed https://launchpad.net/bugs/63280 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
