title: setWindowFlags(Qt::WindowStaysOnTopHint) hides Qt Window
body: <p>I want to make my Qt Window stay on top. When <code>setWindowFlags(Qt::WindowStaysOnTopHint)</code> is executed, the window becomes hidden (on Windows 7).</p>
  
  <p>I've also tried:</p>
  
  <pre><code>Qt::WindowFlags flags = windowFlags();
  setWindowFlags(flags | Qt::WindowStaysOnTopHint);
  </code></pre>
  
  <p>And, it still does the same. What did I do wrong here?</p>