A newly registered user can be seen in the backend, but they don't receive any confirmation of their registration. What's more there is no message like "Hello, ..." on Guru site. Furthermore, the same user can be seen as logged in in JomSocial component, but they cannot log out from there, cause there is no user toolbar and Joomla logout module does not work.
Addtional Info (htaccess / cPanel / PhpMyadmin):