[Samba] Accessing Samba Mac Server from windows machine using NIS users and password

[filippo]

Dear sirs,
i have a network with Windows, Unix and Mac OS X 10.3 machines.
I have a NIS server on the irix machine, and i am able to login on Unix as well as on Mac OSX machines using the NIS accounts.
In the PDC for the windows machines i have the same users (and passwords) of the NIS enviroment, as a matter of fact i am able to connect to Unix folder shared with samba without any problem.
But i am unable to see Mac folders shared with samba, the only way for doing that is to add local users on mac.
Otherwise i have an "invalid password" error.
I am using samba 3.0.2.
Is there a way for being able to access the Mac folders using NIS accounts, that is without adding all the users locally to the Mac computer?
Thanks in advance.
Regards
Filippo