If you're getting this sort of issue:
$ smbclient //192.168.9.9/I$ /mnt/winshare-I -o rw,user="MeUser",password="somepassword" -v
Domain=[WINPC_NAME] OS=[Windows 5.1] Server=[Windows 2000 LAN Manager]
tree connect failed: NT_STATUS_ACCESS_DENIED
Then follow us on our Samba / CIFS Connectivity page for the resolution to the issue. Hope this helps out!