I was wondering if Mihaid tried mounting the NAS after uninstalling and reinstalling cifs, samba and network shares automount but before installing zeroconfig? Zeroconfig could be a red herring.
I didn't.
The devil on my shoulder is telling me go and uninstall zeroconfig, but I've struggled so much with this to work so I won't do it. I'm of the opinion that if it ain't broke don't fix it. Presumably zeroconfig does not have any detrimental effect.