I solved my problem. If the url of registration is profile/register, when you hit the "register" button, it will redirect you to the profile/, but thats the url of "someone's" profile, so you don't have access. I've changed the url (In menage sef urls) of "profile" into "my-profile", and it works fine now. Ofcourse, before that i needed to remove CB link from the main menu, because it redirects you to the "profile".

Hope you can understand my version of English :)

Cheers.