QEvent::TouchEnd missing from secondly touched widget if released last

#include <QApplication>
#include <QWidget>
#include <QDebug>

class Widget : public QWidget
{
  public:
    Widget(QString name)
    {
      setObjectName(name);
      setWindowTitle(name);
      setAttribute(Qt::WA_AcceptTouchEvents);
    }
    virtual bool event(QEvent *event)
    {
      if ( event->type() == QEvent::TouchBegin ) {
        qDebug() << objectName() << "QEvent::TouchBegin";
        event->setAccepted(true);
        return true;
      }
      else if ( event->type() == QEvent::TouchEnd )
        qDebug() << objectName() << "QEvent::TouchEnd";
      else if ( event->type() == QEvent::MouseButtonPress )
        qDebug() << objectName() << "QEvent::MouseButtonPress";
      else if ( event->type() == QEvent::MouseButtonRelease )
        qDebug() << objectName() << "QEvent::MouseButtonRelease";
      return QWidget::event(event);
    }
};

int main(int argc, char **argv)
{
  QApplication app(argc, argv);
  Widget w("Widget 1");
  w.show();
  Widget w2("Widget 2");
  w2.show();
  return app.exec();
}