Cheers Neil, yep - Lexmark is the same, when the cart is changed it changes the print heads too.
Ok yes, I'm a cheapskate and refill my carts myself, however they always work fine until left - and I just know now after every holiday that the dreaded printer chore will be waiting again (NO comments about not having holidays pls

).
Neil....just seen some deserved praise for you from a customer selling an ST4s on Flebay - looks nice too - (Sigh) - Maybe one day
F