Hi abaker,
Thank you for using the Support Forum. Please try using the Global Driver and see if that will fix the issue. If the GLobal driver cases the same issue please consider contacting your support centre for further assistance.
We have several different models of WorkCentres 7120, 5735, 7535 are all models we've seen this issue on. The user will be connected to the printer for a month or more and suddenly they will stop being prompted for the accounting codes. Other users of the same printer will be unaffected at the same time. The only solution we've found is to remove the driver package from print management on the end user's computer, then reconnect to the printer and let it download the driver from the server again. This will work for a while, but then occasionally the user will have the same problem weeks or months down the line. We are using the individual driver for each model, not the global driver. The clients are Windows 7 x64.