ISSUE SUMMARY:
No registration runs through facebook. Follow the instructions (the only difference in relation to the documentation with instructions when creating an application on facebook, there is no room to create a link to the mobile site, somebody was in the presentation JomSocial about creating integration with Facebook)
You can not set up an account through facebook.

STEPS TO replicate:
1 follows the description of the documentation step by step
2 not only find a place to enter the address of the page when creating mobile applications facebook, but I do not know if it has any connection with the case, but I type a web address correctly - www.akademiamunina.pl
3 Paste correct data to JomSocial with facebook - app id key
4 On the button appears to registration / login facebook, I click on it
5 No registration occurs, there is a system information
RESULT
Message pops up, like that:
Application configuration does not allow the use of the URL .: At least one of the following URLs is not allowed by the application's settings. The address must match the URL of a site or page canvas or domain must be a subdomain of one of the application domains.
EXPECTED RESULT
Registration in the system JomSocial through facebook
BROWSER
Opera, Chrome

Cześć Paweł.

I already answered you in previous (Polish written) thread: www.jomsocial.com/forum/facebook-connect...-z-integracja#137331