1) Set the User Creation setting in JFBConnect to "Facebook User Only". That will automatically create accounts for users.
2) Please make sure that Skip Activation is enabled in the CB Profiles section of JFBConnect. Also, make sure Skip Joomla Activation is disabled in the main JFBConnect Configuration area.
Finally, if you have fields marked as "Required" in Community Builder, please make sure that they have a mapping enabled from Facebook's profile. If you have any required fields in CB that are not being imported into, Community Builder will not let us save the user, which will cause a lot of issue. For more information, see:
www.sourcecoast.com/extensions/jfbconnec...s#CB-required-fields
Hope this helps, and good luck!