samba - Jan 2015 - Wrong username or password adding Windows machine to domain

Hi all,

I have tried to add a Windows 7 embedded machine to a Samba4 (Version
4.0.9) domain an get an error related to wrong username or password.

I have other Windows 7 Ultimate working fine with this domain. I could join
a Windows 2008 AD (running as Windows 2003 level) with this windows 7
embedded, but he refuses to join Samba domain.

Could you guys help me?
Thanks in advance.