title: YouTube API calls to playlist feed fails when playlist IDs are not prefixed with "PL"
body: <p><em>(I've <a href="http://code.google.com/p/gdata-issues/issues/detail?id=3599" rel="nofollow">submitted a bug report to YouTube</a> but thought someone here might have some insight)</em></p>
  
  <p>It seems that the YouTube API is suddenly (past 24 hours or so) demanding a leading "PL" in playlist IDs when requesting playlist feeds. Here's how you can reproduce:</p>
  
  <ol>
  <li>Make an API call to <a href="http://gdata.youtube.com/feeds/api/playlists/PL83FF64CDA043CBC4?v=2" rel="nofollow">http://gdata.youtube.com/feeds/api/playlists/PL83FF64CDA043CBC4?v=2</a></li>
  <li>Make an API call to <a href="http://gdata.youtube.com/feeds/api/playlists/83FF64CDA043CBC4?v=2" rel="nofollow">http://gdata.youtube.com/feeds/api/playlists/83FF64CDA043CBC4?v=2</a></li>
  </ol>
  
  <p>You'll notice that the actual playlist identifier (83FF64CDA043CBC4) is the same in each case, but the first call is prefixed with "PL".</p>
  
  <p>The playlist itself is viewable at both</p>
  
  <ol>
  <li><a href="http://www.youtube.com/playlist?list=PL83FF64CDA043CBC4" rel="nofollow">http://www.youtube.com/playlist?list=PL83FF64CDA043CBC4</a></li>
  <li><a href="http://www.youtube.com/playlist?list=83FF64CDA043CBC4" rel="nofollow">http://www.youtube.com/playlist?list=83FF64CDA043CBC4</a></li>
  </ol>
  
  <p>According to <a href="http://apiblog.youtube.com/2012/08/playlists-now-with-more-pl.html" rel="nofollow">this blog post</a>, the API should be <em>tolerant</em> of the leading "PL", but in this case it seems to demand it.</p>
  
  <p>Anyone have some insight into the sudden change?</p>