Qt 4.8, Windows: Custom Drawings Using PaintEvent & Setting widget attribute Qt::WA_Translucent, Not working On Windows if Qt::WindowTitleHint is set

// mainwindow.cpp

#include "mainwindow.h"
#include <QPainter>

MainWindow::MainWindow(QWidget *parent)
: QWidget(parent)
{
this->setWindowFlags(this->windowFlags() | Qt::FramelessWindowHint);
this->setAttribute(Qt::WA_TranslucentBackground);
}

MainWindow::~MainWindow()
{

}

void MainWindow::initTimer()
{
m_timer = new QTimer();
connect(m_timer,SIGNAL(timeout()),this,SLOT(update()));
m_timer->start(1000);
}

void MainWindow::paintEvent(QPaintEvent *pe)
{
QWidget::paintEvent(pe);
QPainter painter(this);
painter.beginNativePainting();
QPen pen;
pen.setStyle(Qt::SolidLine);
pen.setColor(Qt::red);
painter.setPen(pen);
painter.drawLine(this->rect().topLeft(),this->rect().bottomRight());
painter.endNativePainting();
}

// main.cpp

#include <QtGui/QApplication>
#include "mainwindow.h"

int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.resize(500,500);
w.initTimer();
w.show();

return a.exec();
}