Forum Facebook error question

[محروم.كوم]

I followed the guide for facebook connect. The facebook logo appears on my forum, and the ID/secret is correct. It's giving me this error though:
Invalid Argument

The Facebook Connect cross-domain receiver URL (http://www.mysite.com/forum.php) must have the application's Connect URL (http://www.mysite.com/forum.php/) as a prefix. You can configure the Connect URL in the Application Settings Editor.




what does that mean and how do i correct it? __DEFINE_LIKE_SHARE__