Good question. All LabVIEW errors are negative, so it may be carrying over this generalization when dealing with your COM server. I'm not sure if this would be the case. This is really a question for LabVIEW experts though, so I would post the question to the LabVIEW section of Developer's Exchange
here so LabVIEW users can respond.
Best Regards,
Chris Matthews
National Instruments