User login, drive mappings and script

Our system has 3 win200 servers. Our main server roles are PDC, RID, Domain Naming Master,the other two are dhcp, dns and print. When user logs in to the network he/she can be authenticated by any of this three servers.
Problem that i am having is that when user is authenticated by our main server they are logged in to the system, but none of their drives are a mapped, login script is not getting executed and they can not use any network resources. But if user with aministators rights logins he is not having any problems, scripts are executed and drives are mapped properly.
Thank you for the help