Password authorized role not being enabled by default

Hi

 I'm having a problem (in an 11.1.0.7 db) where a role with a password has been assigned to a user (as a default role), but the user doesn't appear to have any access to the role objects - If i disable the password authentication on the role, the user can access the role objects

As far as I can tell from the documentation, the password authorisation setting should be over-ridden if the role is set as a default role, but this doesn't seem to be the case  - is there something else I need to be doing ?

any help greatly appreciated.....