Since my Youtube API code did not work i´ve decided to start from the beginning and tried the example code from https://developers.google.com/youtube/iframe_api_reference?hl
I was able to reproduce in http://jsfiddle.net/77PJB/3/.
function onPlayerReady(event) { event.target.playVideo(); }
I filed this internally. You can file it in public issue tracker if it's not filed already, to be notified once it's fixed.