[Dovecot] shared namespace subscription

I test dovecot 2.0.9 and i use a shared namespace. I use this to see inbox for user2 in shared namespace for user1.

When user2 unsubscribe for inbox , the shared inbox disapear too from shared namespace in user1 list.

This is normal ? I believe that whatever subscription has user2 , if the director is shared , only the indexes will be copyied from the original place, not along with the subscription.