UPDATE: Facebook\'s API has changed a lot since this question was posted. This question is not relevant anymore.
I\'m making an iOS application for
It appears this is a known issue, see https://developers.facebook.com/bugs/379697955378489, you should subscribe to the bug to track its progress.
I don;t know for iOS, but at least for web, you can use the graph api to post to a fan page, and that does not require for the user to have liked the page. Posting to a page via the graph api is still available after the fb changes on February 7th (I've just tried)