PDFCreator stuck in print queue

When we print from PDFCreator, it gets stuck in the printer spool for PDFCreator. Even if I right click the PDFCreator icon in Devices and Printers and go to properties to print a test page, it gets stuck and won't finish. Any ideas?

sorry for the trouble.
Did this happen after an update, or is it a fresh PDFCreator installation?
Does manually launching the PDFCreator.exe trigger the conversion of all the jobs in the queue?

Best regards