[Samba] OpenLDAP + SASL + Samba

[Mentesan]

Hi,

I've configured SASL to autenticate against Active Directory (it's 
working, OK)
I've configured OpenLDAP to autenticate against SASL, using 
'pass-through autentication' (it's working too)
I've managed to configure ypldap too, if I set the user password with
  smbldap-passwd <user>
the user can login on the samba system, it works, no problem.

But my objective is to autenticate the user against AD, just the 
password, there's no problem if I need to create each user on the LDAP 
system and use just the password on the AD side.

I thought it would be possible to configure Samba + LDAP to autenticate 
against AD, since LDAP on the 'pass-through' configuration is working, 
that is, LDAP is autenticating against Active Directory by SASL.

So when I set the "userPassword" attribute on LDAP to:
userPassword: {SASL}fabio at my.domain

I can authenticate via LDAP (ldapsearch) but not via Samba.

Is it possible to get it working like that? Is there another way to get 
this setup working?
Am I totally crazy and trying to do an impossible configuration?

My best regards,
Fabio Almeida