Some users that I support use a local (non-replicating) application that prints to 4" x 7.5" cards. Periodically, some of them report that their print settings for this application have been lost, and are set at 8.5" x 11" with 1" margins.
My investigation into this has taught me that print settings are stored in desktop6.ndk, because deleting it consistently causes customizations to be lost. However, I am not able to identify anything else that will lose print settings. Can you weigh in with your observations of what loses page settings?