[ubuntu] Remove global menu bar from *Firefox* (22.0)

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http://ubuntuforums.org – Yesterday all was working fine. Firefox did not use the global menu bar and selected other applications did e.g. Nautilus. This morning suddenly Firefox started using the global menu bar. Nothing that I have done so far has fixed that, although with apt-get autoremove ... (as discussed elsewhere in this forum) other applications are now not using the global menu bar. So right now Firefox is the only application using it and yet the main one that I don't want to be using it. I think that this morning FireFox was updated via Update Manager (automatically offered and I accepted). I've rebooted (Hardware)