I've changed the following line in main.cpp file of your application: Code: viewer.setOrientation(QmlApplicationViewer::ScreenOrientationAuto); to Code: viewer.setOrientation(QmlApplicationViewer::ScreenOrientationLockLandscape); and it work's as expected. For some reason ScreenOrientationAuto sets HILDON_PORTRAIT_SUPPORTED flag on app's window. With current portrait mode policy it means that the window won't be blacklisted.
viewer.setOrientation(QmlApplicationViewer::ScreenOrientationAuto);
viewer.setOrientation(QmlApplicationViewer::ScreenOrientationLockLandscape);