See my reply to Re: Manager Position Sorting in OrgChart Box.
"Within the AdminConsole there is a section called Application Wide Settings. In it is "RFC Trace".
Use this (see instructions on p50 of "OrgChart_VSN40_SP1_Admin_En.pdf" for example) to trace the call to SAP and confirm the input parameters. You can then replicate direct into SE37 and record a test case in the Test Data Directory.
I believe you will need to add an enhancement to resolve this. It won't take you long (couple of hrs)."