[Samba] Problem with quota on samba

[pierre.casenove at almerys.com]

Hello,
I have a problem with quota under linux and samba : the OS detects that 
the user is overquota but it can still write on disk.
Here is what I want to do:
- 1 Active directory under WIN 2K
- 1 Linux server (Gentoo distribution) design to offer personnal storage

I have activated the user and group quotas on the desired partition:
/dev/sda8               /home           ext3 noatime,usrquota,grpquota     
0 2 

The quotas are correctly working with a limit set to 500MB (soft limit at 
500MB, hard limit at 526MB)

I have registered the server onto the AD server.

The nsswitch.conf file has been edited to add winbind:
passwd:      compat files winbind
shadow:      compat files winbind
group:       compat files winbind

And finally here is my samba configuration (which must be buggy):
  [global] 
    workgroup = DOMAINE 
    netbios name = stk2n1 
    winbind separator = + 
    idmap uid = 10000-20000 
    idmap gid = 10000-20000 
    winbind enum users = yes 
    winbind enum groups = yes 
    template homedir = /home/%D/%U 
    template shell = /bin/bash 
    security = ADS 
    encrypt passwords = yes 
    realm = DOMAINE.local 
    password server = adsrv.domaine.local #the name of the  Active 
directory server
    server string = stockage %h 
 
[home] 
        path = /home 
        read only = no 
        guest ok = no 
        guest only = no 
        directory mask = 0770 
        create mode = 0770 


If I put more than 500MB on the network folder, the overhead is detected 
but the user can still write on the disk:

Disk quotas for  user DOMAINE+fff7878 (uid 10179) : 
Filesystem         blocks       soft       hard     inodes     soft hard
/dev/sda8  669592* 500000  524288              64   20000   24000

Where am I wrong?

Thanks in advance for your help, please ask for any further information 
that might be missing.

Pierre