title: Jquery UI 1.10.x Dialog drag issue on large body height
body: <p>In short: When You have document height > window height, scroll down and open dialog - You can not drag it in Firefox. Bug occured only in jQuery UI 1.10.x</p>
  
  <p>How to reproduce:</p>
  
  <p>jsfiddle: </p>
  
  <p><a href="http://jsfiddle.net/mefa/zrNNZ/15/" rel="nofollow">http://jsfiddle.net/mefa/zrNNZ/15/</a></p>
  
  <pre><code>&lt;html&gt;
  &lt;head&gt;
      &lt;meta content="text/html; charset=UTF-8" http-equiv="content-type"&gt;
      &lt;title&gt;Jquery UI FF dialog bug - jsFiddle demo by mefa&lt;/title&gt;
      &lt;script src="//code.jquery.com/jquery-1.9.1.js" type="text/javascript"&gt;&lt;/script&gt;
      &lt;link href="/css/result-light.css" type="text/css" rel="stylesheet"&gt;
      &lt;script src="http://code.jquery.com/ui/1.10.3/jquery-ui.js" type="text/javascript"&gt;&lt;/script&gt;
      &lt;link href="http://code.jquery.com/ui/1.10.3/themes/smoothness/jquery-ui.css" type="text/css" rel="stylesheet"&gt;
      &lt;style type="text/css"&gt;
      html {
          font-size:12px;
      }
      body {
          height: 2000px;
      }
      &lt;/style&gt;
      &lt;script type="text/javascript"&gt;
      $(window).load(function(){
       $(function() {
          $( "#dialog-modal" ).dialog({
            height: 150,
            modal: true
          });
        });
      });
      &lt;/script&gt;
  &lt;/head&gt;
  &lt;body&gt;
  &lt;div title="Basic modal dialog" id="dialog-modal"&gt;
      &lt;p&gt;Drag this dialog to bottom of document in Firefox&lt;/p&gt;
      &lt;p&gt;Bug only in jquery ui 1.10.x&lt;/p&gt;
  &lt;/div&gt;
  &lt;p&gt;Sed vel diam id libero rutrum convallis. Donec aliquet leo vel magna. Phasellus rhoncus faucibus ante. Etiam bibendum, enim faucibus aliquet rhoncus, arcu felis ultricies neque, sit amet auctor elit eros a lectus.&lt;/p&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>Video: <a href="http://www.youtube.com/watch?v=_J8aepYHg4U" rel="nofollow">http://www.youtube.com/watch?v=_J8aepYHg4U</a></p>
  
  <p>So, assume U have a Jquery UI Dialog, and tag <strong>&lt;body&gt;</strong> has vertical scroll (for example You have much content, big table for example). Assume Your window height is <strong>800</strong> px and document height is <strong>2000</strong> px; So U need to scroll down, to get all contents.</p>
  
  <p>Then You scroll down, over the window height, for example to <strong>1000px</strong>, open dialog. After that <strong>You can't correctly drag</strong> it into any other position, because it's jumps like a mad.</p>
  
  <p>Ive recorded a demonstration, based on the <strong>original jquery ui examples</strong>, so no one can say I missed or corrupted something.
  Only one thing Ive changed is body css attr "height", and set it to 2000px to simulate large document.</p>
  
  <p>I appreciate any advice/fix.</p>