Comment 6 for bug 717682

The implementation of QMenuBar in Qt4.7 does not hold onto focus while panning horizontally through menus with the mouse or keyboard. In the brief pause between one menu closing and another opening, the focus is returned to the application, causing the flicker.

This behaviour can be seen in other native Qt apps like Qt Creator or KDE apps like Kate. However it is more noticeable in thus dbus-based menus, due to the fact that each menu display causes dbus traffic which elongates the pause between menus.

GTK menus do not have this focus problem, hence the indicator bar does not exhibit this issue.

Have reported to upstream Qt: https://bugreports.qt.nokia.com/browse/QTBUG-20532
Will lower priority for now.