ERR TOO MANY REDIRECTS

Something is altering our URLs and causing the issues you're seeing. When being redirected from Facebook, the user is being sent to:
/index.php?option=com_jfbconnect

That URL is missing a lot of required parameters. Can you let me know:
* Are you running any security extensions on your site? I asked a similar question here for an issue that may be related
* Can you disable any SEF extensions or settings you may have enabled, as those could be altering our URLs. If that works, we can help you re-enable them.
* Is there anything special on your site that may be causing alterations to URLs or redirections in general?

Hopefully the above gets you started. We'll need to narrow down the cause though to get things figured out.

Thanks,
Alex

Glad we're making progress. I don't know the specifics of Artio, but in all SEF extensions (including Artio) there is a way to have it 'skip' modifying URLs from specific components. You'll need to prevent Artio from altering any URLs from JFBConnect (or com_jfbconnect).

Again, I don't know the specific way to do that.. you may have to contact them.. but hopefully it's an easy process in their admin area.

I hope that helps, but should you run into anything else, just let me know.

Thanks,
Alex