Well I've selected my theme name from the dropdown menu in the settings pane in wp-admin and enabled HTML5 mode (also in wp-admin) if thats what you mean?
I have noticed though that single quotes are being outputted in the src, see below:
<script type='text/javascript' src='http://localhost:8888/kettlesyard_wordpress/wp-content/uploads/jw-player-plugin-for-wordpress/player/jwplayer.js?ver=3.3.2'></script>
<div id="jwplayer-1-div" class="custom player">
<div id="jwplayer-1"></div>
</div>
<script type='text/javascript'>jwplayer('jwplayer-1').setup({"flashplayer":"http:\/\/localhost:8888\/kettlesyard_wordpress\/wp-content\/uploads\/jw-player-plugin-for-wordpress\/player\/player.swf","width":"210","height":"170","controlbar":"over","dock":"false","autostart":"false","icons":"true","playlist.position":"none","playlistsize":"180","repeat":"none","shuffle":"true","bufferlength":"1","smoothing":"true","stretching":"uniform","wmode":"opaque","mute":"false","volume":"90","skin":"http:\/\/localhost:8888\/kettlesyard_wordpress\/wp-content\/plugins\/jw-player-plugin-for-wordpress\/skins\/kettlesyard\/kettlesyard.zip","controlbar.idlehide":"true","backcolor":"#ffffff","file":"","modes":[{"type":"html5","config":{"streamer":"","provider":""}},{"type":"flash","src":"http:\/\/localhost:8888\/kettlesyard_wordpress\/wp-content\/uploads\/jw-player-plugin-for-wordpress\/player\/player.swf"},{"type":"download","config":{"streamer":"","provider":""}}],"playlist":[{"title":"MYKY12T1X5G7M - Duncan Robinson","creator":"","author":"","date":"2012-03-29 10:50:00","levels":[{"file":"http:\/\/localhost:8888\/kettlesyard_wordpress\/wp-content\/uploads\/2012\/03\/MYKY12T1X5G7M.mp3"},{"file":"http:\/\/localhost:8888\/kettlesyard_wordpress\/wp-content\/uploads\/2012\/03\/MYKY12T1X5G7M.mp3"},{"file":"http:\/\/localhost:8888\/kettlesyard_wordpress\/?p=281"}],"image":"http:\/\/localhost:8888\/kettlesyard_wordpress\/wp-content\/uploads\/2012\/03\/houseasartw_thumb.jpg","description":"","mediaid":"186","id":"186"}]});</script>
Is this correct?