Whilst mate-panel loads none of the shutdown/logout buttons work
This I believe is the crux of the problem. So if we can sort this out I think all will be good.
I've noticed that when I run mate-panel this error message comes up on the terminal:
(mate-panel:3374): GLib-GObject-CRITICAL **: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
(mate-panel:3374): GLib-GObject-CRITICAL **: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
The panel appears to run properly with the exception that the logout/shutdown buttons don't work. One other difference is that lockscreen does not work anymore - with gnome-panel I could still lockscreen
