Техподдержка спрашивает:
The only instances when the printer key would change would be when an important part of a printer would be changed, or the firmware would be changed, which would mean a change in the overall configuration of the printer, leading to a different printer-key.
Can you confirm with the customer if he changed something on the printer? Is the printer-key changing constantly? Did he change the firmware on the printer?
Откуда таки следует, что меняться просто так оно не должно, что-то все-таки делается "не то". М?