title: How come HTML5 video plays inconsistently in Firefox 11?
body: <p>I have the following HTML5 video code on my homepage and it acts strange in Firefox 11.</p>
  
  <pre><code>&lt;video width="900" height="508" autoplay="autoplay" controls="controls"&gt;
      &lt;source type="video/webm" src="http://www.mysite.com/MovieClip.webm"&gt;&lt;/source&gt;
      &lt;source type="video/mp4" src="http://www.mysite.com/MovieClip.mp4"&gt;&lt;/source&gt;
  &lt;/video&gt;
  </code></pre>
  
  <p>When the homepage on my site loads, I see in the place of the video the following error message:
  <strong>"No video with supported format and MIME type found."</strong></p>
  
  <p>However, when I open up the media path <strong>"http://www.mysite.com/MovieClip.webm"</strong> directly, in a new tab, it loads the media just fine (using the internal Firefox HTML5 video player)!</p>
  
  <p>Then, right afterwards when I go back to my homepage and refresh the page, it now loads the video just fine! Any ideas on why this is happening and how to fix?</p>
  
  <p>Thanks in advance!</p>