I'm trying to run a trivial example code written in Python-Qt (PySide). The application contains a button that should open a new QMainWindow with (automatically generated) back button inside the same application. Unfortunately it doesn't do that. It opens a completely new application window with no back button.

Source code here:

Does anyone have any clue about what I'm missing here? Or could it be a bug in PySide implementation? It seems that the whole parent-child-connection between these two QMainWindows is missing.

I'm using
- libqt4 version 4.6.0
- pyside-qt4 version 0.2.3

Any help is greatly appreciated.