I have a major account that has been buying and using FS 9100 and 9500 machines and printing from a specialized application that we cannot change. When there job prints(not through a windows driver)several of the pages are coded to be two sided. However since they had always been using non-duplexing machines(HP),they wanted all the new machines to print all pages single sided. So we were able to get the deal by disabling the duplex units as if it was an option and this works great with no problems. Now they just purchased their first FS 9120 and we configured it the same as all the other Kyoceras and it still whants to duplex. It throws a jam every time the 2 sided page gets to it.
Do any of you possibly have any idea's as to what may be different, or another idea for a soultion?

Looking over the FRPO user reference manual, The only switch I see of possible help is N7. It is titled "Duplex feed mode" and value of 3 is "Coventional, manual" mode. I don't know if this will just print single sided or not. For all I really know it may display a message to place the paper in the MPT to print the 2nd side. Text gives no further clue.

Have you also updated to current firmware level yet?

Why dont you create a logical printer on port 9103 for example and enter a prescribe to duplex(or not). This is the easiest way in my mind.

We are in the process of creating a filter so that when the embedded duplex command is seen it will turn off the duplex. But so far it seems like unless we can strip the embedded command off the data stream, that it tries to duplex.