QGraphicsView QPixmap cropped

Question

Hi,i'm on ubuntu lucid with qt4

The image is cropped,look by yourself by compiling this (it appear only whith QGraphicsView,when i diplay the widget,it's okay)

#include <QApplication>
#include <QtGui>

int main (int argc, char *argv[])
{
    QApplication app(argc, argv);
    QLabel* lab = new QLabel;
    QPixmap img(3000,3000);
    img.fill(Qt::red);
    lab->setPixmap(img);
    QGraphicsView* w = new QGraphicsView(new QGraphicsScene);
    w->scene()->addWidget(lab);
    w->show();
    return app.exec();
}

(seems QGraphicsView don't repaint his components....strange)

EDIT:reproduced on windows 7