title: MP4 not supported in Firefox?
body: <p>If I paste the following URL directly into the address bar in Firefox, the video plays just fine:</p>
  
  <p><a href="http://distilleryvesper1-13.ak.instagram.com/744b42900fab11e3a34522000ae80008_101.mp4" rel="noreferrer">http://distilleryvesper1-13.ak.instagram.com/744b42900fab11e3a34522000ae80008_101.mp4</a></p>
  
  <p>However, as soon as I wrap it in HTML5 video tags (as in this <a href="http://jsfiddle.net/X34z4/" rel="noreferrer">Fiddle</a>), Firefox claims that the video isn't supported:</p>
  
  <pre><code>&lt;video width="612" height="612" controls&gt;
    &lt;source src="http://distilleryvesper1-13.ak.instagram.com/744b42900fab11e3a34522000ae80008_101.mp4" type="video/mp4"&gt;
  &lt;/video&gt;
  </code></pre>
  
  <p>I'm using Firefox version 24.0.</p>
  
  <p>Any ideas?</p>