How to use Facebook accessToken from an iOS app to use in Rails / Facebooker

Question

Hi there. I'm using iOS SDK to do Facebook Connect in an iPhone application, I can successfully login in and get the accessToken from the Facebook instance but I'm not able to use it from a rails/facebooker.

I do the call on the iPhone app:

NSString * url = [NSString stringWithFormat:@"http://localhost:3000/fb_login?access_token=%@",[self.facebook accessToken],nil];

I'm passing the accessToken to an action on the rails app like this:

#auth_token comes from the iOS SDK.
facebook = Facebooker::Session.create('app_key','secret_key')
facebook.secure!(:auth_token => auth_token)

but I get Facebooker::Session::MissingOrInvalidParameter: "Invalid parameter"

Any thoughts? Thanks in advance.