QMenuBar does not work on OSX

The menu entries in my app do not appear on OSX.
It is a simple helloworld app, and the binary is
generated with py2app.

The same application when used with pyqt works, ie.
the menu entries appear and are adjusted as the documentation
mentions at http://developer.qt.nokia.com/doc/qt-4.7/qmenubar.html

The demo app is at github. You can view and checkout the pyside branch here:
https://github.com/wummel/hellopyqtside/tree/pyside

Note: this bug report is transferred from http://bugs.pyside.org/show_bug.cgi?id=1103 since it still applies.