Hello papaqube.
You properly configured the whole set of domain integration. Good work.
What you need is a step forward. To achieve completly the process you should edit the configuration of the [Public] section from the /etc/samba/smb.conf (or any path it is in).
Add this:
Code:
browseable = yes
public = yes
And you should be able to browse your Public folder with any user/pass registered in the Active Directory.