title: slideUp and slideDown cause a jump in text in Firefox 12?
body: <p>I have a code as below:   </p>
  
  <pre><code>$(function(){
  
      $("#ani").slideUp(600,function(){
           $(this).text('13').slideDown(600);        
      });
  })
  </code></pre>
  
  <p>And HTML code as below:  </p>
  
  <pre><code>&lt;div&gt;Comment: &lt;span id="ani"&gt;12&lt;/span&gt;&lt;/div&gt;
  </code></pre>
  
  <p>When page has been loaded slide will affect <code>Comment:</code> text. <a href="http://jsfiddle.net/uYXMB/2/" rel="nofollow">I have written this code in jsFiddle and you can watch it there.</a>
  What is the problem. I wrote <code>display</code> and <code>height</code> css properties for the outer div but gain no success ;(</p>