Qt/Windows Event Dispatcher Problem in modal dialogs

From Mac bug:

Please compile the attached example with Qt 4.6.1/Windows.

• Open the modal dialog by clicking the button inside the mainwindow.
• Click the modal dialog's "Clicke Me!" button
• A timer is started within a local QEventLoop
• After 3 secs. the local QEventLoop is being quit by the timer
• The invokeSlot is invoked using Qt::QueuedConnection (via QEvent)
• This slot is not being called untill further UI events are generated (mouse, keyboard, ...)
• Move the mouse => voila

If you move the Timer/Eventloop/Invoke stuff into the MainWindow it works as it should, so I guess that modal/session stuff has something to do with the bug.
With Qt 4.5/Cocoa the same example works correctly too.

The real application that suffers from this bug uses QEventLoop and QNetworkAccessManager to have synchronous SOAP calls from withing a QDialog - the QTimer is just a simulation of a SOAP-result to keep the example minimal.