QML Listview has memory leaks when QList<QObject*> model is used

Please check the attached application it was implemented according to http://doc.qt.nokia.com/4.7-snapshot/qdeclarativemodels.html#qobjectlist-based-model
QObject* destructor called, delegate destructor called, gc() called, but it still shows increasing heap usage.
The increasing heap can be checked with pmap -x <pid> too.
valgrind says that despite of the destructor of the DataObject is called it leaks. If no delegate is specified then no memory leak happens.