this qt code crashes

qt table to graphics scene

void MainWindow::on_actionAddTable_triggered()
{
    //add table
    QTableWidget* newTable = new QTableWidget( 3, 3);
    newTable->setHorizontalHeaderLabels(QStringList()<<"1"<<"2"<<"3");
    newTable->setVerticalHeaderLabels(QStringList()<<"A"<<"B"<<"C");
    qDebug() <<" table labled";
    // row mod(26) = letter
    QWidget * thisPage = pageStack->currentWidget();
    QGraphicsView * thePage = dynamic_cast<QGraphicsView*>(thisPage);
    QGraphicsScene * thisScene = thePage->scene();
    qDebug() << "scene aquired ";
    QFocusFrame * tableProxy = new QFocusFrame(newTable);
    qDebug() << "new frame";
    thisScene->addWidget( newTable);
    qDebug() <<"table added";

}