Ok. Seems to me if you disconnect on any page, you should go to the main net page, since presumably you were in some part of net play. I think this should avoid ending up in a "lobby" after disconnecting

#include <QtGui/QApplication>
#include "mainwindow.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    return a.exec();
}