QDockWidget gets hidden when closing application

Hello,
I have a QMainWindow that holds a QDockWidget. On closing the app I want to save the visibility of the dock widget.

When I close the app via the shortcut Alt + F4 odr via the x-Button in the upper-right corner the visibility of dock widget always is set to false. On the next application start the dock widget is not shown because the QSettings ini-file (where the settings of the app are stored) says "false" to the visibility of the dock widget.

When I close the application via QCoreApplication::quit() the dock widget seems to stay visible right before the app is closed. On the next application start the dock widget is shown because the ini-file true"false" to the visibility of the dock widget.

I am running the app solely on Win XP, so I have no idea if this is Windows specific behaviour for QDockWidget.

I use QDockWidget::isHidden() to ask for the dock widgets visibility when quiting my app and to store the visibility.
Any idea where this strange behaviour might come from, or how to store a dock widgets visibility?

Try connecting your settings saving slot to the aboutToQuit () signal.

This sadly does not help.
The dock widget is still hidden "before" the signal aboutToQuit() is emitted :(.

Override the closeEvent of the mainWindow to save your settings.