QTableView with custom datamodel doesn't update on insert rows (on linux)

I tried extending the Simple Tree Model Example to include a nice
decoration icon and allowing for updates to the data. I think I have
done this correctly however... If I connect a QTableView before populating the model,
the newly added data isn't displayed. A QListView, QtreeView and even a QComboBox work
as expected. I attached a screenshot of the output displayed on my screen.
I also attached a minimal example.

I'm running a 64bit linux system, a quick post on the qt-interest maillinglist gave as feedback that it also fails on 32 bits ubuntu but works on XP (Qt 4.7.1)