Run the Autotune configuration tool again. Go to the FB App settings page, and then click the "Refresh" button at the top. It's likely that you haven't updated your FB App configuration settings for the new domain. Update any recommendations that are provided. If that was the problem, the login still works on Facebook's end, but they won't actually notify JFBConnect that the login occurred (since it happened on an incorrect domain).
If that's not it, let us know, and we'll help how we can!
Thanks,
Alex