Monique,
Facebook changed their authentication method quite extensively in January of this year. We had support for the new updates in our original 4.0 release in August last year, and sent out newsletters, blog posts, and communicated it in many other ways. Unfortunately, to our knowledge, v3.x no longer works with Facebook authentication. We haven't done any testing with the 3.x series in over 6 months, so it's possible it was working, but from everything we know about Facebook changes, it shouldn't.
You'll need to upgrade to a 4.x release in order to get things going again.
Hope that helps,
Alex