Symbian CBA buttons/Status Bar pop/s up while using Phonon::VideoWidget

Scenario:
A QMainWindow based application. The MainWindow has a QStackedWidget. The QStackedWidget has 2 QWidgets, say wid1 and wid2, on its stack. wid2 has a phonon::videoWidget. wid1 is the QStackedWidget::CurrentWidget first up. Fix the app to landscape mode.

Use case 1:
Move from wid1 to wid2 and call showfullscreen on wid1.
Observation:
Blank Symbian CBA buttons (2 of them) pop up at bottom of the screen.

Usecase 2:
Move from wid1 to wid2. Lock and unlock the phone (or set an alarm to go off while in wid2, or connect/disconnect a usb cable to the phone, ... any system event which pushes the app back)
Observation:
3 regular Symbian CBA buttons along with the status bar pop up.

Please find a sample app which reproduces this issue, attached.

Note 1: Copy a mp4 video (name it test.mp4) to c:\videos or change the media url to suit yourselves.
Note 2: Define ISSUE1 in TestStackWidget.cpp to reproduce use case 1 or undefine to reproduce the other use case.