Text not center-aligned in QSvgGenerator output

Check the output of this program in for example Firefox or Konqueror:

#include <QtGui>
#include <QtSvg>

int main(int argc, char *argv[])
{
QApplication app(argc, argv);

QSvgGenerator generator;

generator.setFileName("out.svg");

QPainter painter(&generator);
QRectF rect(0, 0, 100, 40);
painter.fillRect(rect, QColor(127, 127, 127, 63));
painter.drawText(rect, Qt::AlignCenter | Qt::TextWordWrap, "Hello World");
}