To Lonkero, your suggestion is not applicable, because the program is happy with the installation of the printer in kixtart. The problem only crops up when I use Kixtart to set the default printer.
To Arend, I am already using a vbs script almost identical to the one you have written up there. so I have got my script to work. The point of my post is to highlight the fact that there is an issue or bug with the setdefaultprinter function. I do agree with Lonkero, that the program is an older style program so probably uses a legacy based way of determining which printer is the default. But as it works when I manually set the default printer, to me it means that the kixtart function is not accurately replicating the result that should occur.
Thanks