[Samba] acl's, Samba4 and rw shares

[steve]

Hi
I'm trying to make a share called dropbox rw for members of a group.

/usr/local/samba/etc/smb.conf
[global]
     server role = domain controller
     workgroup = CACTUS
     realm = hh3.site
     netbios name = HH3
     passdb backend = samba4
     template shell = /bin/bash
[netlogon]
     path = /usr/local/samba/var/locks/sysvol/hh3.site/scripts
     read only = No
[sysvol]
     path = /usr/local/samba/var/locks/sysvol
     read only = No
[home]
     path = /home/CACTUS/%USERNAME%
     read only = No
[profiles]
     path = /home/CACTUS/profiles%USERNAME%
     read only = No
[dropbox]
     path = /home/dropbox
     read only = No

I have

mkdir -m 0770 /home/dropbox
chown steve:debusers /home/dropbox
chmod g+s /home/dropbox/
setfacl -Rm g:debusers:rw,d:g:debusers:rw /home/dropbox/

  getfacl /home/dropbox/
getfacl: Removing leading '/' from absolute path names
# file: home/dropbox/
# owner: steve
# group: debusers
# flags: -s-
user::rwx
group::rwx
group:debusers:rw-
mask::rwx
other::---
default:user::rwx
default:group::rwx
default:group:debusers:rw-
default:mask::rwx
default:other::---

If I create a file in the share using touch (or right click on the share 
 > new in explorer), no problem:

steve2 at hh3:~$ touch /home/dropbox/hola
steve2 at hh3:~$ ls -l /home/dropbox/hola
-rw-rw----+ 1 steve2 debusers 0 2012-02-16 12:11 /home/dropbox/hola

But, if I create the file in my home folder (or the mapped home folder 
drive on Windows) and then copy or drag it to the share, I don't get 
group rw:
steve2 at hh3:~$ touch hola2
steve2 at hh3:~$ cp hola2 /home/dropbox/
steve2 at hh3:~$ ls -la /home/dropbox/hola2
-rw-r-----+ 1 steve2 debusers 0 2012-02-16 12:12 /home/dropbox/hola2

None of the smb.conf force group nor acl commands are recognised. I 
could cron the setfacl as a workaround or get the users to chmod it to 
660 but, well. . .

1. Is it possible to copy a file to a folder and have it inherit the 
parent folder permissions?
2. How do you chmod 660 on windows?

Thanks,
Steve