Contact List Cleaner
Contact list Clean-up problem
Clean up Concact
In short....no, it doesn't seem to still be working 100%.....and has definitely been noted.
But I don't think it's a Plus! problem as the information in Messenger's own "See who has added you to their contact list" feature is also incorrect and that is where Plus! gets its information from.....so it's most likely some kind of server synchronisation issue....something I've also noticed when adding new contacts, being told that the "Service is unavailable at the moment" and that contacts will be added at a later date