7.6.4 CreatePrintJob

My Customer is encountering something very strange. Recently when they click on the button to Print the currently displayed window a popup is displayed to save the file As.
Here is the code on the button:
if event.clickCount == 1 and event.button == event.BUTTON1:
job = system.print.createPrintJob(event.source.parent)
job.print()

Any thoughts on why it would be prompting to save a file?
Thanks
Rennie

Try looking at the default printer. Maybe it is trying to print to a PDF generator.