It's fixed, broke down and called Sage. The PDF Converter appears to have been corrupt. Thanks to Ryan @ Sage, we stopped the print spooler in services, which ironically deleted the Sage PDF converter. He reinstalled it and everything worked fine. As a side note, this customer was also having problems generating PR DD Stubs from their workstations (under previous 4.40 version). They have the path for the PDF set to go to another server and Ryan suggested that W2008 doesn't play well with legacy forms and storing them on another server. He called it the 'third server syndrome'. Have advised client and will see how this works.