[Samba] world permissions edition

[Arnaud FLORENT]

hello

i am using samba 3.0.25c on sarge

i try to allow domain users to edit directory permission on public share 
with XP  client using using the native security dialog box.

with these share properties:

    nt acl support = yes
    directory mode = 2777
    force directory mode = 2770 
    directory security mask = 0777 
    force directory security mode = 0770 

new directory are created with drwxrwsrwx mode, that's great

from XP security dialog box, i get full control for user, group and 
Everyone, that's great

but i can't remove Everyone Full control. When i use apply button, the 
full control permission is back for everyone...

i can't explain it because
it's not forced (force directory mode = 2770  force directory security 
mode = 0770)
and user shoumd be allowed to remove it (directory security mask=0777)

what's wrong?

thank you....