general samba config (just global) ... Ubuntu... works fine for MacOS/OSX and Win Clients...

smb.conf

[global]
        workgroup = WORKGROUP
        server string = %h server (Samba)
        map to guest = Bad User
        obey pam restrictions = Yes
        pam password change = Yes
        passwd program = /usr/bin/passwd %u
        passwd chat = *Enter\snew\s*\spassword:* %n\n *Retype\snew\s*\spassword:* %n\n *password\supdated\ssuccessfully* .
        unix password sync = Yes
        syslog = 9
        log file = /var/log/samba/log.%m
        max log size = 1000
        name resolve order = lmhosts host wins bcast
        unix extensions = No
        load printers = No
        dns proxy = No
        panic action = /usr/share/samba/panic-action %d
        invalid users = root
        create mask = 0664
        force create mode = 0664
        security mask = 0664
        force security mode = 0664
        directory mask = 0775
        force directory mode = 0775
        directory security mask = 0775
        force directory security mode = 0775
        veto files = /.DS_Store/
        follow symlinks = No
        wide links = No
        inherit permissions = No
        strict locking = No