Getting FBML Error unknown tag "fb:like" error with Facebook app

I've been looking at this for ages now and I cant find anything on the net that provides a solution. When trying to use the tag...

...this is embedded on a tab canvas. The 'Like' button appears when using the app locally, however, it doesn't appear when used on the facebook site. I get this error:-

FBML Error (line 264): un开发者_如何学运维known tag "fb:like"

I have FBML enabled in the settings. I've also tried using the iframe alternative with no luck.

Any ideas?

PS.. I'm using CakePHP

doesn't seem to be available inside Canvas. According to Facebook's document, there is a simple version and a version for XFBML but I can't find the document pointing to that one either. :(

The new documents is a mess.

This is the official document about XFBML like button

http://developers.facebook.com/docs/reference/plugins/like

If you're starting from scratch, you should build a IFrame based Canvas application instead of a FBML based one. IFrame Canvas applications can run normal JavaScript, including the JS SDK which supports the <fb:like> tag, for example: http://apps.facebook.com/fbrelll/xfbml/fb:like.

<div>
<fb:iframe src="http://www.facebook.com/plugins/like.php?href=http%3A%2F%2Fexample.com%2Fpage%2Fto%2Flike&amp;layout=standard&amp;show_faces=true&amp;width=450&amp;action=like&amp;colorscheme=light&amp;height=80" scrolling="no" frameborder="0" style="border:none; overflow:hidden; width:450px; height:80px;" allowTransparency="true">
</fb:iframe>
</div>

look at this ,using fb:iframe,it works well~~have a try!