以下のようにsthを試し、n番目が発生します-
<script src="http://static.ak.connect.facebook.com/js/api_lib/v0.4/FeatureLoader.js.php" type="text/javascript"></script>
<script type="text/javascript">   
   FB_RequireFeatures(["XFBML"], function(){ 
       FB.Facebook.init("<?=$apiKey?>", "channel/xd_receiver.htm"); 
       var api = FB.Facebook.apiClient;
       Facebook.streamPublish();    
   }); 
</script>