QVideoWidget+QMediaPlayer renders any QTreeWidget in the application unresponsive

When a QVideoWidget is added to a QMediaPlayer with setVideoOutput, the application writes "QBackingStore::flush() called with non-exposed window, behavior is undefined" a few times into the output and any QTreeWidget instance used in the application is rendered inoperative.

This issue appears only under macosX it does not happen under ubuntu or windows.

The bug can be simply reproduced by adding
QTreeWidget* tree = new QTreeWidget();
tree->addTopLevelItem(new QTreeWidgetItem(QStringList("test1")));
tree->addTopLevelItem(new QTreeWidgetItem(QStringList("test2")));
...
hLayout->addWidget(tree);

to Player::Player(QWidget *parent) in the "Qt5.0.2/5.0.2/clang_64/examples/multimediawidgets/player" sample.

The tree control is not responsive, the user can not change selection.

when the line player->setVideoOutput(videoWidget) is commented out the control works ok, and no errors are write to the output, howe ever than of cause the player is unusable.