Request and response controls are needed to get the directory server to sort returned objects by a specified attribute.
See also: http://tools.ietf.org/html/rfc2891
Add Control support for RFC 2891 - LDAP Control Extension for Server Side Sorting of Search Results http://www.faqs.org/rfcs/rfc2891.html
Sorry, this issue is a duplicate!
Fixed with DIRAPI-137
Closing the resolved issues.