title: JPopUpMenu problem with adding menu items
body: <p>I'm creating JPopUpMenu with following code:</p>
  
  <pre><code>JPopupMenu popup1 = new JPopupMenu();
  JPopupMenu popup2 = new JPopupMenu();
  
  JMenuItem freeze = new JMenuItem("freeze");
  freeze.addActionListener(new FreezActionListener(this));
  
  JMenuItem unfreeze = new JMenuItem("unfreeze");
  unfreeze.addActionListener(new UnFreezActionListener(this));
  
  JMenuItem sortU = new JMenuItem("sort");
  JMenuItem sortD = new JMenuItem("sort");
  
  
  
  popup1.add(freeze);
  popup1.add(unfreeze);
  popup1.add(sortU);
  
  popup2.add(freeze);
  popup2.add(unfreeze);
  popup2.add(sortD);
  </code></pre>
  
  <p>After executing this code,  <code>popup2</code> menu works fine but <code>popup1</code> has only <code>sortU</code> item.
  If I add menu items first to <code>popup2</code> and then to <code>popup1</code>,  then <code>popup1</code> works fine and <code>popup2</code> doesn't.</p>
  
  <p>Is it normal behavior or did I miss something ?<br>
  I've searched about this but can't find anything </p>