I'm working on inserting into LDAP (Microsoft Active Directory) also. After reading the PowerExchange for LDAP User Guide (version 9.1), the chapter title "LDAP Mappings" explains that the GPK and GFK values should be a unique value from the source. And that the GPK/GFK ports should be linked to the SAME values. This is assuming your LDAP Target Definition has a child group defined. The GFK port only exists in the child group. I'm referring to GPK port in the parent group. There is a GPK port in the child group also, and this should uniquely identify the child records that are going to be inserted. I simply used a sequence generator transformation to populate that GPK child port. I haven't been able to get past an error in the session log so I can't tell you for sure that this worked.