That's definitely a ridiculously long log-in time. There are a lot of variables in the login process based on the user's location and the nearest Facebook servers and your server horsepower in general. However, there's no way it should take that long.
Looking at your site, I see you're using a Gavick template. You also have the Facebook integration in that template enabled, which could be conflicting with JFBConenct and our Facebook communication. Can you please go into the template settings and disable their Facebook integration. Our Autotune Error Checker should be notifying you of the possible conflict, and you can use it to also check when you resolve the issue.
Beyond that, if you still see slow times, please disable any JFBCProfile plugins you have enabled and disable the "New User Redirection" and "Returning User Redirection" settings in JFBConnect. If that speeds things up, then re-enable those features one-by-one and test to see if there's a slow-down again. If so, let us know what seems to be causing it to go slow.
Hope that helps get you started,
Alex