Logon Message

I Server running “Windows2000 Server” and Terminal Services. I am the “Admin” user of the server. I have 5 workstations running “Windows2000 Pro” that are connected to this server, users of these workstations are “Domain Users”. I can logon to “all”computers, through Terminal Services. However, none of the other users “Domain Users” are able to logon to the server through “Terminal Services”. the Logon Message I get back is “The local policy of this system does not permit you to logon interactively.” All the permissions in “user” properties are set to accept “Terminal Service Users”. What can I do that will allow “Domain Users” to logon to “Terminal Services”???
HELP!!!
Lynnn Sims