title: jQuery ui dialog dragging issues
body: <p>I used the jQuery ui (jquery-ui-1.10.3) dialog pluggin for one of our products, and found a possible "problem":
  When the hosting page is small or the current view of the hosting page is scrolled to the top, dragging an openned dialog box behaves as what is expected. The problem start to manifest when hosting a dialog in a large page which is scrolled to somewhere not at the top, in which case the dialog box starts to jump around during dragging. It happens to both IE 9 and the latest Firefox (21.0).</p>
  
  <p>The page is dynamically generaed, complex and has to be long. I am not familiar with fiddle, but it seems to have no option for jQuery-ui lib option that I can use. </p>
  
  <p>More specifically, I found if I scoll the hosting page 100px down (so the top 100px of the hosting page is 'feed' into the top border of the browser window) then when I drag the dialog, instead of it following the mouse, it jumps down 100px so that it is out of the mouse capture. </p>
  
  <p>The dialog is initiallized as </p>
  
  <pre>
  $(element).dialog({ 
      autoOpen: false, width: 950, height: 820, 
      modal: false, resizable: true, draggable: true
  });
  </pre>
  
  <p>My questiong is: 1) does any one else has the same issue? 2) If so, is this an setting issue or a bug.</p>
  
  <p>Any expert here can help me with it?</p>