I write a dll using Novel CLDAP SDK, because no dev files from openLDAP could be use in windows. basically, they are same, and I found the same problems yet. ldap_simple_bind could not work , but ldap_simple_bind_s is ok. the former return "Operations Error", maybe it is the problem of LDAP Server, ( debian lenny, openLDAP 2.4.11 deb) gtalk:freeespeech@gmail.com