I have a M611 printer that keeps running into print jams everytime I try to print from either the network or just printing out printer menu. I have replaced the fuser, transfer roller unit, all the sensors from the tray to exit i have replaced the paper size actuator unit . when it jams it says mismatched paper size but the display is set for 8 1/2 x 11 and i have tried setting auto size and manual size. the page gets to about 75% done, then states there is a jam in the right door.