Now that the deprecated netinfo is removed, including all command line interfaces, in 10.5/Leopard, it appears Webmin 1.410 (detecting Darwin 2008) can not find the Users and Groups from the new format xml files in the directory.
The passwd, passwd.master and group files are only functional in single user mode.
In short, webmin does not display any users and groups under Leopard client (and probably server, too). Trying to create a user fails silently and returns you to the screen below.
Apple's statements about this change:
Apple shows how to create users with dscl:
Most of these server command lines work on client as well:
PAM authentication isn't working. Of course, nidump doesn't generate a password file on the fly anymore because it doesn't exist.
Of course, this change in architecture has implication for Unix
authentication and Usermin as well. Happy to help test.
Sorry for the duplicate submission; this one should be proper.