[turba] How "groups" works on turba?

[J Miguel Aceff S]

Hello everybody,

I hope to be clear with my problem

I have an installation of "Horde WebMail 1.2.4" authenticated with IMAP. 
Turba configuration is with the sql driver (in postgres).

Everything worked properly until I created 2 groups to classify my users 
(Family and Work).

 From that moment all users except the administrator failed to see their 
address books. And searching on database I saw that each time they 
entered to turba "horde"created a new record in turba_shares.

When I delete groups, users automatically returned to see the address 
book (and indeed all duplicates addres books).

My questions are:

1) I create groups on my installation to classify my users?
2) I need to create any hook to know which group horde take it?
3) I can guide what I'm doing wrong in my installation?

Thanks in advance