OK...I've got a stake in this: When printing on two sides, Canon imagePRESS calculates the shrinkage on each sheet and automatically compensates and calculates image size so that crop marks line up. In addition, imagePRESS is built from the ground up to register sheet sizes up to 13 x 19.2, not letter size sheets. The reason many of these digital "presses" have trouble with front to back registration is they are designed to register letter size sheets. This creates many of the issues faced when attempting over and over again to line up registration/crop marks on tabloid sheets and greater. There are reason's we pay more for some presses over others. That is just one of them.