Input focus is not moved back to text for certain menu actions in Lyx in WMs like Awesome, dwm, and without any WM at all

There's a bug that appears in Lyx (LaTeX editor) when used in window managers like Awesome and dwm, and without a window manager at all (in an xterm session). When using Alt+I to go to "Insert" menu, then choosing an item there using arrow keys (or a shortcut letter key), after pressing Enter to select the menu item the input focus is not moved back to the text but remains in the menu. E.g., pressing the "f" key will open the "File" menu then.

See this bug report for exact instructions to reproduce the issue and for further details: https://awesome.naquadah.org/bugs/index.php?do=details&task_id=960
Note that the bug appears for several (or possibly all) kinds of menu items in the "Insert" menu. Also note that everything does work fine if not pressing Alt+I to jump into the Insert menu directly, but Alt to move the focus to the menu and then navigating using arrow keys.

Lyx devs said it probably is a QT bug: http://www.lyx.org/trac/ticket/7984#comment:12