Controlling media curl in print-zone

In an inkjet printing apparatus an inkjet printhead has a plurality of inkjet nozzles which eject ink onto media located within a print-zone. A drive shaft is located upstream of the printhead and is incrementally rotated to advance the media. The drive shaft has a longitudinal axis, a first radius over a central length and a second radius less than the first radius at a first recess and a second recess, each said recess being peripheral to the central length. A plurality of pinch devices stabilize the media against the drive shaft. A first guide is aligned with the first recess and is spaced from an axis of the drive shaft by a first distance which is less than the first radius. A second guide is aligned with the second recess and is spaced from the axis by a second distance less than the first radius.