Error 126/1797 during silent install

We install pdfcreator on our clients with WPKG using:

One some of our computers installation fails, and I can not find any common denominator.

In PDFCreator program folder there is a "SetupLog.txt" including these errors:

Install printerdriver for Win2kXP2k3 (32bit):
 Drivername : PDFCreator
 Environment : Windows NT x86
 Result: Error 126 = The specified module could not be found

 Printername: PDFCreator
 Drivername : PDFCreator
 Portname   : PDFCreator:
 Result: Error 1797 = The printer driver is unknown

After some Googleing I found how to add the virtual printer manually pointing on the driver, and then it works. However, during the next reinstall it will fail again.

Any thought on what causes this and how to fix this permanently?
The problems began after upgrading from 1.0.2 to 1.2.0.