cannot login using rdp over internet, not a connection problem.

I have 2 servers, one is 2008 server and 2003 server.  they are both dc's.  2003 is main one.  we have a remote office that uses rdp to login to both servers using the administrator account.  the wierd thing is we can login using the same account to the 2008 server but cannot login to the 2003 server.  

i know its not a connection problem because the server over rdp from remote office asks for username and password with the ip at the top so it connects but will not authenticate.  from the same computer in remote office, i can access other server in remote location using rdp and same account. any ideas?

the error is "to logon to this computer, you must be granted the terminal services right."  etc.