please update to latest version in particular to libxfce4util-4.4.0-0ubuntu3, it may help
-- [apport] xfce4-menu-plugin crashed with SIGSEGV in g_node_children_foreach() https://launchpad.net/bugs/94199 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
