Power PDF v2.1 print jobs are held in the printer queue
AccuRoute v5 is the culprit (they've identified it as a known issue). The solution is to modify the ports registry key that will then allow Nuance to attach to a printer.
Omtool fixed the issue in their newer release (v6), however, clients that are still using v5 will need to modify the Ports registry. Advise them to contact Omtool for details and assistance.