Bug#766100: In XFCE, menu from system tray icon does not stay open

[Gedalya]

Package: libgtk-3-0
Version: 3.14.1-1

When clicking on the system tray icon for nm-applet or gnote, the menu 
remains open only as long as the mouse button is held down.
The menu can be made to stay open by landing the click on a menu separator.

https://bugzilla.redhat.com/show_bug.cgi?id=1149335

Better described here: https://bbs.archlinux.org/viewtopic.php?pid=1467359