I can reproduce this right now on the Xubuntu utopic daily snapshot (20140917) when I don't have the Indicator Plugin added to my Xfce panel.
I also saw the same problem on by Xubuntu trusty system back in July.
I can reproduce this right now on the Xubuntu utopic daily snapshot (20140917) when I don't have the Indicator Plugin added to my Xfce panel.
I also saw the same problem on by Xubuntu trusty system back in July.