LDAP - ldap_search_st return error code 1

["Lim Hock-Chai" <Lim.Hock-Chai@xxxxxxxxxxxxxxx>]

I used Scott K's program as an example to create a rpg program to connect to a 
ldap server.  The program seems to be able to connection to the ldap server 
(using ldap_simple_bind_s) without any problem.  However, when it do 
ldap_search_st, the server return an error code of 1 (Operations Error).  Is 
there anything that I can do to find out what cause this error?
 
Note: I'm trying to connection to a MS exchange server to get the address book. 
 I tried on the browser  <ldap://ldapserver/> ldap://ldapserver and get the 
same error.  My first though was that ldap server is the problem.  However, we 
got some guys here that use Evolution by Ximian that connection to the same 
ldap server and it seems to be working ok for them.