[Samba] share permissions

[João Alberto M. dos Reis]

Hi list,

I need to create the following share:

user1 can create a file in the share but can't erase or change;
user1 can just read the file when he creates it;

user2 can delete and change the file user1 has created;


I did like this: 

user1 is member of group group1;
user2 is member of group group2;

[share]
        path = /home/share
        read only = No
        write list = @group2
        create mask = 575
        force create mode = 0575
        force user = user2
	force group = group2

When user1 creates a file in "share" the files gets the permissons
right: user2  group2 r_xrwxr_x filename 
and can't delete or change "filename"

But user2 can't delete or change the "filename" even if he is in group2.

1. If I "su - user2" in shell, I can delete and change it because I have
group permissions for that, but via windows I can't.

2. Is that a problem in my configuration groups/users (my samba is
working with ldap)?

   I already tryed to make group2 the primary group of user2, without
any success.

TIA,

Joao Reis.