title: HTML5 Audio currentTime property is not always the same
body: <p>I have an Audio element, with a random source, from wikipedia, I attach a listener to the timeupdate, and I put a console.log(this.currentTime) on it, and I always get different values, can somebody explain me that.</p>
  
  <p>HTML:</p>
  
  <pre><code>&lt;audio id="track" src="http://upload.wikimedia.org/wikipedia/commons/a/a9/Tromboon-sample.ogg" controls preload="auto"&gt;
  &lt;p&gt;Your browser does not support the audio element&lt;/p&gt;
  &lt;/audio&gt;
  </code></pre>
  
  <p>Javascript:</p>
  
  <pre><code>window.onload = function(){
    var track = document.getElementById('track');
  
    track.ontimeupdate = function(){
      console.log(this.currentTime);
    };
  };
  </code></pre>
  
  <p>Result:</p>
  
  <pre><code>0
  0.241375
  0.492853
  0.743976 
  0.995482
  </code></pre>
  
  <p>Again:</p>
  
  <pre><code>0.241815
  0.49318
  0.744024
  0.995427 
  </code></pre>
  
  <p>Thanks</p>