samba - Sep 2013 - Windows 7 32 bit doesn't "upload" the profile to the server on logout but Windows 7 64 bit does

Hello,

I have a Samba 3 PDC running on SLES 11 SP3. All the machines have 
joined the domain correctly, and users can log to their profiles 
correctly.
On Windows 7 64 bits profile roaming works nicely without any problem 
(login is just a bit slow and it takes about 45 seconds while logout is 
really fast).
On Windows 7 32 bits profiles are "downloaded" from the sever
correctly
when a user logs in but on logout they are not "uploaded" back to the 
server. So users work on the locally cached copy without any issue but 
they cannot move to any other machine because their .msprofile.V2 
directory is empty.
If a new user logs in before on a 64 machine and then on a 32 machine 
the profile that has been created on the 64 bit machine is used but then 
is not updated on the server.
Users can write to their profile folder on the server. All the machines 
have SP1 but I had this problem also without SP1. I don't see any 
relevant error on any log, or any error dialog and users are marked as 
"roaming".

On the server side:
I'm using ldap as backend for users and I'm using ext3 mounted with 
"rw,acl,user_xattr,usrjquota=aquota.user,grpjquota=aquota.group,jqfmt=vfsv0".
Quotas are still not used, I will work on that as soon I get everything 
working.

This is part of my smb.conf:

[global]
         map to guest = Bad User
         logon path = \\%L\profiles\.msprofile
         logon home = \\%L\%U\.9xprofile
         logon drive = P:
         usershare allow guests = No
         domain logons = Yes
         domain master = Yes
         local master = Yes
         netbios name = MUNCH
         os level = 65
         preferred master = Yes
         security = user
         wins support = Yes

      [....]

[profiles]
         comment = Network Profiles Service
         path = %H
         read only = No
         store dos attributes = Yes
         create mask = 0600
         directory mask = 0700