I just tried to register and was able to successfully log in afterwards. Some things to note though that may be causing you issues:
* You look to be using Community Builder. To properly import the Facebook profile and create the user in CB, any fields in CB marked as "required" must have a field mapped to them in the Profiles area of JFBConnect. If you don't map a field from Facebook, you must not mark that field as required. CB won't let us save a user to their tables if any required fields are missing.
Hope that helps get you started, but if you need anything else, please let us know exactly what isn't working (error messages, something missing, etc).