Comment 47 for bug 872207

For me, the bug appears at random (firefox 9, oneiric). Any menus only stay open until I move the mouse; switching to another window and back generally seems to stop it. I have noticed a couple of other things that might be relevant, though.

Firstly, I use firefox's autoscroll feature (preferences->advanced->browsing). Normally, when I middle click, the autoscroll icon appears, then doesn't disappear until I click again, but whenever the menu bug occurs, the autoscroll icon disappears (and autoscrolling stops) if I point at the autoscroll icon. As far as I can see, the two issues always happen together.

Secondly, when I open a new window using tkinter in a python application, any open firefox and thunderbird menus close - menus in other applications I have tried are unaffected.

For example, the following python 3.x code (replace tkinter with Tkinter for python 2.x) simply opens a window, waits a second, closes the window, waits a second, and repeats. Every time the window opens, open firefox and thunderbird menus close, regardless of whether this bug is in effect.

from tkinter import Tk
from time import sleep
while True:
    tk=Tk()
    tk.after(1000, tk.destroy)
    tk.mainloop()
    sleep(1)