diff -Naur a/lib/weblib.php b/lib/weblib.php
--- a/lib/weblib.php	2011-01-06 12:23:44.000000000 -0800
+++ b/lib/weblib.php	2011-01-06 12:23:55.000000000 -0800
@@ -1503,6 +1503,7 @@
         $config->set('HTML.Doctype', 'XHTML 1.0 Transitional');
         $config->set('URI.AllowedSchemes', array('http'=>true, 'https'=>true, 'ftp'=>true, 'irc'=>true, 'nntp'=>true, 'news'=>true, 'rtsp'=>true, 'teamspeak'=>true, 'gopher'=>true, 'mms'=>true));
         $config->set('Attr.AllowedFrameTargets', array('_blank'));
+        $config->set('Attr.EnableID', true);
 
         if (!empty($CFG->allowobjectembed)) {
             $config->set('HTML.SafeObject', true);