Printer reverts changes after applying them

So I've got this customer who wants us to help him changing the print from 2-sided printing to 1-sided printing.

I log onto the print server (Windows 2008) and open up "Print Management". There I locate the printer and press "Preferences".

I then press the "2-Sided Printing (Duplex)" dropdown menu and change from "Long Edge (Auto)" to "(None)".

Other alternatives are: "Short Edge (Auto)", "Long Edge (Manual)" and "Short Edge (Manual)".

I then hit "Apply", then "Ok".

If I open "Preferences" again, it was as if I did no changes at all. It still shows "Long Edge (Auto)" in the "2-Sided Printing (Duplex)" field.



As a matter of fact, this problem affects all settings/changes I have available to that spesific printer. Worth mentioning that it only affects this printer, which I know ties this issue strongly towards the manufacturer of the printer. But I seek help anywhere I can.



Here is a picture that shows what I'm talking about: drive.google.com/file/d/0B_W9izEiyI24NmpPa1dnY21iWHM/view?usp=sharing