I just resolved a VERY similar issue with a networked Konika Minolta C650 on an XP x86 machine . Whenever the user changed the size of the paper (ie. 11/17; portrait or landscape) in the printer settings VIA "Devices & Printers" OR in a program, and clicked apply, the settings would revert to the default printer settings pulled from the server.
I Had to install the printer as a local port and manually install the latest XP compatible dirvers from the Konika website.
WINNING