diff -urN media_youtube.old/themes/media_youtube.theme.inc media_youtube/themes/media_youtube.theme.inc
--- media_youtube.old/themes/media_youtube.theme.inc	2011-02-14 09:59:57.000000000 +0100
+++ media_youtube/themes/media_youtube.theme.inc	2011-02-14 10:00:23.000000000 +0100
@@ -35,7 +35,7 @@
   $variables = array_merge($variables, $variables['variables']);
 
   $video_id = $variables['video_id'];
-  $variables['url'] = isset($variables['url']) ? $variables['url'] : "http://www.youtube.com/v/$video_id";
+  $variables['url'] = 'http://www.youtube.com/embed/'. $video_id;
   $variables['url'] = check_plain($variables['url']);
   $variables['width'] = check_plain($variables['width']);
   $variables['height'] = check_plain($variables['height']);