We solved our own problem. But here is what we have found for anyone who may be experiencing a similar problem.

If we print the report to one of our network printers and then send that spec to our client, they get an error message that the printer can not be found when they try to print the report.

If we print the report to a local printer (i.e. one attached to LPT1) and then send the spec to our client, there is no problem.

It seems like a "bug" to me, but I guess there is fairly easy work-around