The Facebook app broke the old way of creating an iOS facebook page link. If the app isn't installed the old facebook link works, but when it is installed it just opens the Facebook app to the default page. Fix your app links to Facebook using this url format:
Old iOS Facebook Page Link:
New iOS Facebook Page Link:
The only downside is that the user would have to login via the mobile website in order to "like" your Facebook page. It's certainly better than just seeing the "default" screen in the app. I'm not sure if the new Facebook SDK 3.1 fixes any of these issues, but I haven't seen a solution on Stackoverflow.com
Linking to a facebook page doesn't work from iOS if the new Facebook app is installed.
Linking to the mobile Facebook page with the ?_rdr flag fixes the issue.