[Serusers] Calling other SIP users

Hi, I have my SER working when i try to talk to other SIP servers. However, i cannot make calls inside my own network. I am using LDAP to authenticate my users, and I have sipldap script that circulates in the web. Everything works fine until there, i get the following output when the user exists: sip:username@host isn´t this what was supposed to happen? When i then try to (!lookup("location")) { if (!exec_dset("/etc/ser/sipldap")) { sl_send_reply("404", "Not Found"); break; } else { log(1," sipldap call"); }; }; #!lookup I get the Not Found message. But if i call the following way: username@username_IP the call works fine.. any ideia? Jose Simoes