[Samba] samba + cups

[Fabio]

Hi to all!

I have some problem using samba 3.0.20d and cups. I set cups to
authenticate users (authentication http basic) for /, /jobs and /admin.

When a windows user (authenticated in samba like print user) try to print,
the print job is rejected by cups (cups logs contain username="" and
error=401 Unauthorized).

When a windows user (authenticated in samba like printer admin) try to
print, the print job is accepted in cups (cups logs contain
username="root" and job queued by 'root').

My question is: how cups get credential by samba? (or how samba pass
username and password to cups?)

I need to set up a print server in a lan windows/linux and so I want to
set cups to authenticate users (else linux workstations can print without
control) (windows workstations are authenticated by samba).

I googled a lot but without results, I think that only here I can get this
information.

Thanks to all,
Fabio