I have Ultimate Facebook installed as well as Membership.
If a user clicks on Login > Login with Facebook there is no issue. A new account is made if they don't have one. They are logged into their established account if they already do. They get their default access level with Membership and they're on their merry way. It's a beautiful thing.
If a user goes to Register and clicks Register with Facebook -- rather than the Membership form -- it will recognize them as signed in and pre-fill out their information.
When they click "Regsiter" at the bottom of that page, they get the pop-up asking them to continue (facebook approval window).
If you click Continue, the pop-up goes away and the previous page is behind it (with the pre-filled out facebook info) but stay there forever. "Register" is grey'd out and the progress bars are moving along but nothing is happening.
I'm at a loss of where to even start.