Hello Linux Geeksters. As you may know, Ubuntu 15.04 Vivid Vervet will come with the Locally Integrated Menus feature enabled by default. This feature has been available on Unity 7 and GNOME 3.12 running on Ubuntu 14.04, but it is not enabled by default.
While the Locally Integrated Menus appear only when the users hovers with the mouse, on Ubuntu 14.04, this has been modified on Ubuntu 15.04, the menus being now shown all time.
But, if you don’t like this feature and want to disable it, you have to install dconf-editor:
$ sudo apt-get install dconf-editor
Select com -> canonical -> unity -> integrated-menus and disable the unfocused-windows-popup option.