Jquery UI Dialog go off screen when drag/move.

See it in actions. http://jsbin.com/boviboro/1/edit

Jquery UI Dialog go off screen when drag/move.

This happens when scroll down on the page to click button and open dialog. And when you drag that dialog it go off screen.

This bug occurs on Firefox, IE. It works fine on Chrome, Opera.

OS: Windows 7.

<p>Loaded. Scroll to bottom.</p>
  <div style="height: 1500px;"></div>
  <button type="button" onclick="$('#dialog').dialog('open');">Open dialog</button>
  <div id="dialog"><p>I'm in dialog.</p>
    
  <script>
    $(function() {
      $('#dialog').dialog({
        autoOpen: false
      });
    });
  </script>