The operational attribute "subschemaSubentry" defined in RFC 2251, 6.2 should be exposed under all entries. ApacheDS does only expose that attribute on the root DSE but not under any other node. Some clients rely on that attribute being available under all nodes. Please expose that attribute always. Also compare with http://www.openldap.org/lists/ietf-ldapbis/200103/msg00018.html.