If it is asking for a code when printing, be absolutely sure it did not get turned on for printing in the same place you turned it on for scanning by someone else.
If it has not, then somehow your driver got corrupted, which is not likely since it is more than 1 PC showing the same symptom unless it is server installed and shared.
In any case, on the Windows PC.
Start > Devices and Printers
Right-click the printer and choose "Printer Properties" if Win7 or higher or "Properties" if Win XP or lower.
Select the Configuration tab and set Bi-Directional to OFF, click OK, re-open the properties and set Accounting System to None and click Apply/OK
We would like to have accounting required for scanning at the machine only. For printing, we want it off. We don't want to enter an accounting code when printing from a computer. What we've done is select Xerox Standard Accounting as the accounting method and disabled Service Tracking for all services but Scans. With this setting, most of the time we weren't asked to enter an accounting code. Now all of a sudden, it's always requiring us to enter a code when printing. Any ideas why this configuration doesn't work or if it's even the proper config?