NW6 Server, SP3 and Native File Access for Macintosh installed.

I am trying to troubleshoot a problem, so rather than use the Prosoftclient, I want to try NFA. When I try to connect from OS X (10.2.6)
clicking Go|Connect to Server, enter the IP address, click connect, a
that says "Connect to the file server 'FS1' as registered user" pops
up, but
no matter who I enter as a user, it always reports, "Login Failed -
User, incorrect password, or log on is disabled. Please retype the
name and
password or contact the administrator."

I know that NFA is loaded on the server, and I think that it is loaded

correctly, but don't know that much about NW6/NFA be 100% certain.