Today when I started
gnome-terminal, the menu bar was not integrated into the title bar as usually. Only the Terminal menu point is correctly integrated, all others show up in a separate menu bar.
The Unity setting for that seems still correct and it works also e.g. for Firefox and others.
If I untick the Show Menubar option, I lose the menu entirely, just the Terminal menu point is still there and still correctly integrated into the title bar. All other menu points are gone.
Right-clicking the title bar just brings the normal context menu:
This is not an issue when operating on the guest account! It works perfectly well there and shows all menu points correctly integrated into either the title bar or the panel, depending on the setting.
What is the problem here and how can I fix the menu-into-title-bar-integration again?
I'm using Ubuntu 15.10 with Unity 7.3.2 and gnome-terminal 3.16.2-1ubuntu4.