Firefox crashes when switching windows - problem apparently caused by Global Menu extension

[Adam Brandizzi]

After updating my Ubuntu 12.04 in Sep 24, 2012 (getting Firefox 15.0.1 and firefox-globalmenu 15.0.1+build1-0ubuntu0.12.04.1) my Firefox keeps crashing when I press Alt+Tab (to go either to another application window or to another firefox window). It did not ocurried just after the update (which required me to restart the notebook); actually, it just started to happen some time after this and before it I could alternate between windows without problem.

It is not even possible to just disable the Ubuntu extras plugin - I had to uninstanll it using Synaptic. After that, my firefox stopped crashing.

I attached the output of the `bt` command in gdb.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[penalvch (penalvch)]

Adam Victor Nazareth Brandizzi, thank you for reporting this and helping make Ubuntu better. However, your crash report is missing. Please follow these instructions to have apport report a new bug about your crash that can be dealt with by the automatic retracer. First, execute at a terminal:
cd /var/crash && sudo rm * ; sudo apt-get update && sudo apt-get -y upgrade && sudo apt-get -y install firefox-dbg && sudo service apport start force_start=1

If you are running the Ubuntu Stable Release you might need to enable apport in /etc/default/apport and restart.

Now reproduce the crash, then open your file manager, navigate to your /var/crash directory and open the crash report you wish to submit.
If this fails you will have to open a terminal and file your report with 'ubuntu-bug /var/crash/_my_crash_report.crash' where _my_crash_report.crash is the crash you would like to report. If you get an error that you aren't allowed to access this report you will have to file it with 'sudo ubuntu-bug /var/crash/_my_crash_report.crash'. If you run the command against the crash report and a window pops up asking you to report this, but then never opens a new report, you would be affected by https://bugs.launchpad.net/ubuntu/+source/apport/+bug/994921 . In order to WORKAROUND this, one would need to open the following file via a command line:
gksudo gedit /etc/apport/crashdb.conf

and comment out the line:
'problem_types': ['Bug', 'Package'],

by changing it to:
# 'problem_types': ['Bug', 'Package'],

Save, close, and try to file the crash report again via:
ubuntu-bug /var/crash/_my_crash_report.crash

Please follow https://wiki.ubuntu.com/MozillaTeam/Bugs when you file this crash report so the necessary information is provided.

I'm closing this bug report since the process outlined above will automatically open a new bug report which can then dealt with more efficiently.

Thank you for your understanding.

Helpful bug reporting tips:
https://wiki.ubuntu.com/ReportingBugs