Qt 4.4.1: menu lists are drawn behind top-level-widgets on MacOS for remote X-apps

When Exporting the X11 Display from a linux box to a Mac X11 terminal, the popup list that is displayed by a QComboBox does not display on top of the main qwidget if the QWidget is a Qt::Tool type.

It seems that the menu-behind problem occurs only if the window on which the menu is invoked happens to be of type Qt::Tool, if I change that to Qt::Window, menus work as expected.

This issue has been reproduced on both Tiger and Leopard.

The following test app can be used to reproduce the issue :
#include <QtGui>

class MyWidget: public QWidget
{
Q_OBJECT

public:
MyWidget(QWidget *parent = 0);

private slots:
void doSomething();

private:
QHBoxLayout *layout;
QPushButton *button;
QComboBox *serverCombo;
};

MyWidget::MyWidget(QWidget *parent) : QWidget(parent,Qt::Tool)
{
setWindowTitle("Support Tester");
layout = new QHBoxLayout;
button = new QPushButton ("Do Something");
layout->addWidget(button);

serverCombo = new QComboBox;
serverCombo->addItem(tr("Trolltech (Australia)"));
serverCombo->addItem(tr("Trolltech (Norway)"));
serverCombo->addItem(tr("Trolltech (People's Republic of China)"));
serverCombo->addItem(tr("Trolltech (USA)"));

layout->addWidget(serverCombo);

setLayout(layout);
QObject::connect(button, SIGNAL(clicked()),
this, SLOT(doSomething()));

}

void MyWidget::doSomething()
{
//TEST CODE HERE
qDebug("something clicked");
}

#include "main.moc"

int main(int argc, char *argv[])
{
QApplication app(argc, argv);
MyWidget *myWin = new MyWidget();
myWin->show();
return app.exec();
}