Sounds like you didnt setup the settings right man. i got it working on my site last night.
post your app settings sceeen shot and i might be able to hep you out
Are you asking about styling the form or removing fields?
I would recommend using a third party plugin for the popup to be honest. I found one called popup press thats pretty cool!
Then you can use the usual registration shortcode with your preffered modifications etc.
In the facebook permissions it also requests profile picture and user pictures. Facebook recently changed a lot of the info with the social login.
subscribing to this post 🙂
UP!
Same issue as andy,need control of where user posts are posted or i need another solution 🙁