title: Qprogressbar stop sliding
body: <p>for an application in Python  I am working on, I need to show  a sliding progressBar with QT 4.7 , I can do it,but it is sliding only as far a QmessageBox is visible,it is very ennoing,I tried in many different ways to keep it sliding without messageBox without any success,I did not find anything about it on internet;this is my code for showing the bar:</p>
  
  <pre><code>    d=QtGui.QMainWindow()
      screen = QtGui.QDesktopWidget().screenGeometry()
      size =  self.progressBar.geometry()
      self.progressBar.move((screen.width()/2)-size.width()/2,(screen.height()/2)-size.height()-100)
      self.progressBar.show()
  </code></pre>
  
  <p>To make it moving I have to add this:</p>
  
  <pre><code>        d=QtGui.QMainWindow()
          infoString="sto creando mmasgisDB!"
          QtGui.QMessageBox.information(d,"Info", infoString)
  </code></pre>
  
  <p>As soon I click on the OK button the bar gets frozen. So I think there is something that I do not know related with QMainWindow, I need the help of someone more expert.</p>