samba - Apr 2002 - password lookup from unix box to password server fails in 2.2.0 (repost)

I am trying to do server security w/ samba 2.2.0
I have set security = server and have set encryption  = yes
I have tried to set the server to a win2k box as
well as to an AS/400 running OS/400 server for network neighborhood.
The log reflects that the unix system is connecting to the server
(and calling winbind though I haven't touched it at all) and then
I finally get this or equiv:

[2002/04/22 14:08:33, 10] lib/username.c:user_in_list(407)
   user_in_list: checking user  in list mgrober
[2002/04/22 14:08:33, 2] smbd/service.c:make_connection(323)
   Invalid username/password for marcsdir []

Do I need to create machines accounts for server security?
What am I missing?