QTreeWidgetItem repainting problem : deselection leaves parent items partially checked untill moused over.

This can be reproduced using the following test code.
First check "Glen Waverley", "Richmond" and
"Mentone", then unchecked "Melb". This issue has been reproduced on various versions of Windows.

#include <QtGui>

class MyWidget: public QWidget
{
public:
MyWidget(QWidget *parent = 0);

private:
QHBoxLayout *layout;
QTreeWidget *tw;
};

MyWidget::MyWidget(QWidget *parent)
{
setWindowTitle("Support Tester");
layout = new QHBoxLayout;
tw = new QTreeWidget();

QTreeWidgetItem *country = new QTreeWidgetItem(tw);

Qt::ItemFlags myFlags = country->flags();
myFlags |= Qt::ItemIsTristate | Qt::ItemIsUserCheckable;

country->setFlags(myFlags);
country->setCheckState(1,Qt::Unchecked);
country->setText(0, tr("Countries"));

QTreeWidgetItem *cities = new QTreeWidgetItem(country);
cities->setFlags(myFlags);
cities->setCheckState(0,Qt::Unchecked);
cities->setText(0, tr("Cities"));

// QTreeWidgetItem *forests = new QTreeWidgetItem(country);
// forests->setFlags(myFlags);
// forests->setCheckState(0,Qt::Unchecked);
// forests->setText(0, tr("Forests"));

QTreeWidgetItem *melbItem = new QTreeWidgetItem(cities);
melbItem->setFlags(myFlags);
melbItem->setText(0, tr("Melb"));
melbItem->setText(1, tr("Yes"));
melbItem->setCheckState(0,Qt::Unchecked);

QTreeWidgetItem *glenItem = new QTreeWidgetItem(melbItem);
glenItem->setFlags(myFlags);
glenItem->setText(0, tr("Glen Waverley"));
glenItem->setText(1, tr("Yes"));
glenItem->setCheckState(0,Qt::Unchecked);

QTreeWidgetItem *richItem = new QTreeWidgetItem(melbItem);
richItem->setFlags(myFlags);
richItem->setText(0, tr("Richmond"));
richItem->setText(1, tr("Yes"));
richItem->setCheckState(0,Qt::Unchecked);

QTreeWidgetItem *mentItem = new QTreeWidgetItem(melbItem);
mentItem->setFlags(myFlags);
mentItem->setText(0, tr("Mentone"));
mentItem->setText(1, tr("Yes"));
mentItem->setCheckState(0,Qt::Unchecked);

QTreeWidgetItem *osloItem = new QTreeWidgetItem(cities);
osloItem->setFlags(myFlags);
osloItem->setText(0, tr("Oslo"));
osloItem->setText(1, tr("Yes"));
osloItem->setCheckState(0,Qt::Unchecked);

QTreeWidgetItem *bonnItem = new QTreeWidgetItem(cities);
bonnItem->setFlags(myFlags);
bonnItem->setText(0, tr("Bonn"));
bonnItem->setText(1, tr("Yes"));
bonnItem->setCheckState(0,Qt::Unchecked);

tw->addTopLevelItem(cities);

layout->addWidget(tw);
setLayout(layout);
}

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