Form redirect destination works in Drupal, but not through facebook

I've got a form set up here:

http://drupal6.ngphost.com/facebook

It's set to redirect you to here and does work when you fill it out on the Drupal site:

http://www.facebook.com/pages/Webolutionary/92962103354

I set it up in a tab on my Facebook page here:

http://www.facebook.com/pages/Webolutionary/92962103354#/pages/Webolutio...

When I submit it there, it submits correctly, but then it tries to redirect to here:

http://apps.facebook.com//node

Obviously a 404. What's going on here? Redirecting to a page within the Drupal site doesn't work either. You always end up with http://apps.facebook.com//[drupal path]