Problems with outlook 2003 and exchange 2000?

I have installed outlook 2003 in my machine. In the domain there is an exchange 2000 server.
Since i have installed outlook 2003, everytime i want to acces my exchange addess list i have a windows pup up that says that i cannot contact to the LDAP server and ask me for a server to type one and put a user and pass if i need????
I tried all the DC servers and with all the Domain Admin users..........but nothing
What im doing wrong??
If i go to CONTROL PANEL, MAIL, from there i can see my two contact lists, the one from a pop3 mail acoount i have, and the LDAP contact list........this is the one i cannot reach.
Thanx
Dioxido

I could make it work people
I just deleted after backup up the .pst file the mail profile from CONTROL PANEL, MAIL and make a new one, with the same data.
And then i put again the .pst into the directory of Outlook.
Thanks anyway.