I’ve been playing a little with Facebook API and I run into problems when trying to use the facebook.feed.publishStoryToUser api call. That call always return 0 (permissions error) for me. I realized that there’s a difference between “Added applications” and “Authorized applications”. So if you just direct the user to the login page (http://www.facebook.com/login.php?api_key=YOUR_API_KEY&v=1.0) from you application your app will end up in the Authorized Applications side. You have to direct the users to your application page in facebook first (http://www.facebook.com/apps/application.php?id=xxxxxxxx&ref=s).