Help with nis password changes

[scott-DPNOqEs/LNQ at public.gmane.org (Scott Ehrlich)]

I normally try not to ask questions until I have done as much research as 
possible, and again, this is the case...

Just after I thought I had my RH5 samba/nis server working fine, I come 
across the inability to update nis passwords.

>From the server as root:

passwd guest1
Changing password for user guest1.
New UNIX password:
Retype new UNIX password:
NIS password could not be changed.
passwd: all authentication tokens updated successfully


For the heck of it:

yppasswd guest1
Changing NIS acount information for guest1 on server.
Please enter root password:
Changing NIS password for guest1 on server.
Please enter new password:
Please retype new password:
Error while changing the NIS password.
The NIS password has not been changed on the server.

The server was rebooted, but that didn't help.

What am I missing?

Thanks.

Scott

-- 
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.