JFBCFriends not working?

Ingmar,
Your idea of how it works is spot-on. I just looked at your page and see the Friends module. However, the URL you've specified (or at least what's showing up on the page) looks like:
/www.your-url.info
(hiding it in case you don't want it public)

That extra / at the beginning is probably what's causing your issue. Can you re-check the parameters and make sure you're not adding that? If not, let us know, and we can investigate more into why that may be getting messed up when inserted on the page.

Thanks,
Alex

Glad to hear that fixed you up. Wasn't actually aware of that requirement, but will keep it in mind (and check our code that we're not doing something wrong).

Either way, good luck!
Alex