Richard,
My invoke function return nothing, hence it does not add the node to NCM database as it should. I have tried with the updated InformationService.pm but no luck. However, if I try manually add (to NCM) via webUI, the new node get synced fine and i can see the node detail data under node detail page. I have also found that I need to provide the machinetype and vendor property along with the sysobjectID to be able to add node to Orion database properly.
What is the returne result of your invoke command?