Active Directory- New User Email

hi guyzz....
in my company network we are using exchange server 2003 and when i created a new user it automatically come to the address book and i can configure the outlook easily. now the problem is that it is not automatically come in the address book . now the new user name came in address book only after i restarted the server. before after i created the new user automatically created the SMTP address and X400 address in the email addresses for that user. now it is not creating after created the new user name. anyone plz help!!!!!!!!!!