drascii

Hi all, i've a problem with two trunk servers (win2003 server standard edition sp1 and win 2000 server sp4). The trunk is external and up and running, but when i try to use folder permission on win 2003 i don't have the possibility to choose users of win2000 server. I can see only the name of the domain, but no users or groups ecc. If i do the same on the server with win2000, everything is ok. I can add users of win 2003 server domain. Any idea? Thanks