Jquery UI FF dialog bug

HTML

<script src="http://code.jquery.com/ui/1.10.3/jquery-ui.js"></script>
<link rel="stylesheet" href="http://code.jquery.com/ui/1.10.3/themes/smoothness/jquery-ui.css">
<!doctype html>
 

<body>
 
<div id="dialog-modal" title="Basic modal dialog">
    <p>Drag this dialog to bottom of document in Firefox</p>
    <p>Bug only in jquery ui 1.10.x</p>
</div>
 
<p>Sed vel diam id libero <a href="http://example.com">rutrum convallis</a>. 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.</p>
  
</body>

CSS

html {
    font-size:12px;
}

body {
    height: 20000px;
}

JavaScript

$(function() {
    $( "#dialog-modal" ).dialog({
      height: 150,
      modal: true
    });
  });