It seems that when creating a Send button, Facebook will not let me send a link to the current iFrame tab / app. The link always gets reduced to just the Facebook page.
For example, I want to create a Send button using the following href: http://www.facebook.com/pages/MyPage/pageid/?sk=app_my_app_id&app_data=My_app_data
But in the send button, the link gets reduced to: http://www.facebook.com/pages/MyPage/pageid
Any ideas on how to get straight to the correct tab and include the app_data?