Kyocera ECOSYS MA3500cix Accounting not being passed through

Just bought myself a Kyocera ECOSYS MA3500cix and tried to set up accounting in the printer, which was fine. But looking at it, even though I’m using the Kyocera-CUPS driver with the ECOSYS 2400cix driver (only one evaluable in colour) the accounting number doesn’t seem to be getting sent to the printer, it just shows up as blank in the printer job area and the printer says invalid credentials.