I am having this EXACT same issue.
I imported a group of users, creating roles for them on the fly. When I started my import I "accidently" deleted the original out of the box roles.
I restored the rows for the deleted rows, and have reviewed my datbase as well (tables: portals, roles, and the the roleid's). It all looks good.
I also have a problem with "registered users", that role is out of synch as well.
Ideas?