The behavior of Unity global menubar for Firefox

Hi. I'm trying to use the Canonical Register iface in javascript, all is ok except with firefox.

I report the problem on stackoverflow without answer:
http://stackoverflow.com/questions/30206099/what-is-the-current-behavior-of-firefox-for-the-ubuntu-menu-bar

Can any of you help me to find what happend and try then to fixed the problem?

This is a copy of what i report on stackoverflow:

I'm trying to development an applet (https://github.com/lestcape/Global-AppMenu) to be used in the Cinnamon desktop. My intention is not modify or create any other code than not be cjs (javascript code). All that i do is:

 1- Connect my applet to the com.canonical.AppMenu.Registrar and the Gtk Dbus API.
 2- Get all object path from the muffin windows manager (a fork of mutter).
 3- Read and ask things over Dbus and then show the result of that. I used all patches of Unity desktop, as I'm a user of Ubuntu 14.04.

Nemo, Nautilus, File-Roller, gnome-terminal, VLC, SMPlayer, Evince, are examples of applications that currently are working. At the moment, I only have a problem with one application, and this application is Firefox.

I'm pretty sure that i do something wrong, just i don't have any idea of what could be.

Firefox called the com.canonical.AppMenu.Registrar service perfectly, i also can trigger the Alt key and firefox don't try to show the menubar inside the window, but after some time (a minute), he emit a layout change signal without menu items, and will show the menubar to the user inside the main window, as is "normally".

My idea is that: this could be, because i'm missing to call some aboutToShow, or because firefox require a confirmation that i receive the menubar, and he required really that this will be done for the same GDBus Connection where he exported the menu bar, but i can not be sure who internally will be handled in that way, as i'm on javascript.

Any way the firefox behavior, apparently is a behavior with an know cause, and what i try to find is the cause of that behavior, to then I will try to find a solution.

Thanks and regards.