QNetworkReply Throttling issue

#include <QHBoxLayout>
#include <QLabel>
#include <QWidget>
#include <QApplication>
#include <QtNetwork>

class MyWidget: public QWidget
{
    Q_OBJECT
    
public:
    MyWidget(QWidget *parent = 0);
    
private slots: 
    void replyFinished(QNetworkReply*);
    
private:
    QHBoxLayout *layout;
    QLabel *label;
    QNetworkAccessManager *nam;
};        

MyWidget::MyWidget(QWidget *parent) : QWidget(parent) 
{
    setWindowTitle("Support Tester");
    layout = new QHBoxLayout;
    label = new QLabel ("Notice that setReadBufferSize does not change the network usage at all");
    layout->addWidget(label);
    
    setLayout(layout);

    nam = new QNetworkAccessManager;
    QNetworkRequest netRequest(QUrl("http://get.qt.nokia.com/qtcreator/qt-creator-1.2.1-src.zip"));
    QNetworkReply *m_reply;
    m_reply = nam->get (netRequest);

    //    m_reply->setReadBufferSize ( 2048 ); //or some other small number
    
       connect(nam, SIGNAL(finished(QNetworkReply*)),
               this, SLOT(replyFinished(QNetworkReply*)));

}

void MyWidget::replyFinished(QNetworkReply*)
{
    qDebug("finished! now remove comments on setReadBufferSize(2048) "); 
}

//This moc include is to get everything in a single file - for quick testing only
#include "main.moc"

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