title: jQuery modal dialog not centering with position flag present
body: <p>I have a site <strong><a href="http://webfro.gs/south/dev/cloud/" rel="nofollow">here</a></strong>... </p>
  
  <p><strong>I didn't create a fiddle because I'm not sure how to replicate the issue with ajax.</strong></p>
  
  <p>When the site loads, there's an auto-popup that brings in an ajax request. </p>
  
  <p>It's way off center and when I add the position flag there, the modal doesn't come up at all. I don't get any syntax errors, so I'm not sure what's wrong. </p>
  
  <p><strong>With this code, the popup opens (but off center)...</strong> </p>
  
  <pre><code>$(document).ready( function() {
      jQuery('#compliance').load('jquery-ajax.html').dialog();
  });
  </code></pre>
  
  <p><strong>And when I add the position flag, it doesn't show up at all...</strong></p>
  
  <pre><code>$(document).ready( function() {
      jQuery('#compliance').load('jquery-ajax.html').dialog({
          position: {my: "center top", at:"center top", of: window },
      });
  });
  </code></pre>
  
  <h2><strong>Edit-</strong></h2>
  
  <p><strong>This is what ultimately worked...</strong> </p>
  
  <pre><code>    $(document).ready( function() {
          jQuery('#compliance').load('jquery-ajax.html').dialog({
          resizable: false,
          modal: true,
          width: 750,
          show: 'fade',
          hide: 'fade',
          position: {my: "center top", at:"center top", of: window }
          });
  });
  </code></pre>