Unfortunately, the 560 code wasn't very friendly in that regard. If a cart was changed before it asked for it, then when a new is inserted, the see thru window is now occluded (toner full), but the printer doesn't know if it's full. The counter resets when the toner level drops to the point that the infra red beam partially goes through and tells the printer that the levle is getting low. When the beam shines through at full strength, then it tells the printer that the cart is empty. Then when you change a cart, it will guess that the next one is new if the windows are blocked with toner.