The "Automatic Resizing" setting still seems to be enabled. When I go to your Facebook Page, the whole page scrolls. With that setting disabled, the 'window' to your site should only scroll.
As for why it's happening, that's an issue with Facebook. The Automatic Resizing option thinks your page is longer than it really is. That can be caused by CSS, content or multiple other issues, but it's not something we can fix on our end.
Please verify that you changed that setting and if you don't see any difference, make sure you also cleared your caches. Hopefully that will get you going. If not, let us know and we can check the admin area of your site for that setting as well.
Thanks,
Alex