Cannot Add User

[Vince Sabio]

I just installed a v5.1 single-boot system from CD. So far, the only 
changes I've made from the initial installation were to configure 
sshd, set the system security level to "moderate" (from "high"), and 
set the system clock; other than that, it's a "clean" installation.

I'm now trying to install Postfix, and the problem I'm running into 
is that I cannot create new user accounts. I created several user 
accounts during installation, and they seem to be fine. But when I 
[manually] create entries in /etc/passwd, master.passwd, and group, 
the entries are 'ignored' -- e.g., a "chown [newuser] [filename]" 
command fails, attempts to su from root into the user account fail, 
etc. When I try to create the user via adduser (using the standard 
defaults), the account creation step fails with the following error:

pw: user '[newuser]' disappeared during update

Again, attempts to 'access' the user (i.e., chmod, etc.) will fail. 
Interestingly, though, if I try to re-create the user, adduser tells 
me that the user already exists -- and a check of the relevant files 
confirms that the entries are there.

I've looked around for a solution to this problem, but haven't found 
one, so here I am.

FYI, the system security level was set to "high" during installation, 
and was then reset to "moderate" after installation, as this system 
is intended to be used as a server (and "high" was too restrictive; I 
couldn't even [find a way to] set the system time correctly).

Appreciate the assistance....
-- 

__________________________________________________________________________
Vince Sabio                                                  vince at vjs.org