Facebook iframe fbxml, page tab problem

Set up a facebook App pulling a site through a canvas iframe (nothing special). So the code its pulling is just your basic html/php. Only exception is the share button within my page,

<script src="http://connect.facebook.net/en_US/all.js#xfbml=1"></script>
<fb:share-button href="LINKTOWEBSITE" type="button">
</fb:share-button>

and everything works fine when I pull it up directly ie: www.mysite.com/facebookex.php

The pro开发者_Go百科blem arises when I put this app within a page tab environment (ie: "Add App to my Page", pull up in a tab) Everything works except for the share button, when clicking on the share button within the tab I get "The provided Application ID is invalid."

Please have a look here : How to make custom share buttons

I'm explaining how to do a custom share button without fbml (and I'm using it inside a page tab application and it's working well ..)

Anyway fb:share-button is not in the facebook documentation anymore, and FBML is in the process of being completely deprecated so it's not a good option for long term ..