Shaun,
Sorry for the issues. Obviously, that's not the correct behavior.
There was recently another report of the strange 500 error on the Overview page. We weren't able to resolve it on that user's site, but would love to have a look at what's happening on yours to see if it's the same. On that site, basically the requests we were making to Facebook were failing in a very strange way. If we could see the same thing on your site, it will help us to have a 2nd example case for comparison.
In the process, we'd install a file explorer extension on your site, and only modify JFBConnect (minimally), and shouldn't interrupt your site during testing. If you're ok with that, please Private Message us a set of admin credentials. You can PM us by clicking the arrow under my name (<---) and hitting the mail icon.
Thanks!