If you are having a post with YouTube video embedded, you must find there is an annoy problem with the latest WordPress 2.1.1. The WordPress 2.1.1 is using TinyMCE 2.0.8, the editor breaks the video. It convert <embed> to <ibed> by mistake.

Actually, the latest TinyMCE 2.1.0 which is releasd at Feb 13 fixed the issue. We can apply the patch for fixing the problem.

--- wp-includes/js/tinymce/tiny_mce.js  (revision 84)
+++ wp-includes/js/tinymce/tiny_mce.js  (local)
@@ -5099,9 +5099,10 @@        // Convert all strong/em to b/i in Gecko
        if (tinyMCE.isGecko) {
-               h = h.replace(/<strong/gi, '<b');
-               h = h.replace(/<em(/?)/gi, '<i');
-               h = h.replace(/<em /gi, '<i');
+               h = h.replace(/<embed([^>]*)>/gi, '<tmpembed$1>');
+               h = h.replace(/<em([^>]*)>/gi, '<i$1>');
+               h = h.replace(/<tmpembed([^>]*)>/gi, '<embed$1>');
+               h = h.replace(/<strong([^>]*)>/gi, '<b$1>');
                h = h.replace(/</strong>/gi, '</b>');
                h = h.replace(/</em>/gi, '</i>');
        }