I've just tried switching to Gnome Shell on the same machine and with the same user, and there I cannot reproduce it. When I switch back to Unity, I can only reproduce it when I choose a theme, e.g. Ambiance, in Appearance settings. This makes me think it is related to the window decorator.
I've just tried switching to Gnome Shell on the same machine and with the same user, and there I cannot reproduce it. When I switch back to Unity, I can only reproduce it when I choose a theme, e.g. Ambiance, in Appearance settings. This makes me think it is related to the window decorator.