Additional profile is not assigned to a user on registration

When an additional profile type is used and is included in the registration, the profile is created, but it is not assigned correctly to the newly created user but the owner is uid 0.

1. Create an profile type.
2. Enable the profile to be inlcuded in the registration form.
3. Either use the Login or the CompleteRegistration checkout pane to register a new user.
4. The profile is created but not assigned to the user.