If you can see this in your 1 bit TIFF, the problem most likely is in the RIP settings. Does changing your line screen or RIP resolution change where the dots start ? Does the RIP have a calibration tool ?
Our Compose Express RIP has a the ability to generate a calibration sweep and of course a Roam tool to preview to 1 bit TIFF files - this is standard with all Harlequin / Global Graphics RIPs - I see XMF is a Adobe PDF Print Engine (APPE), so i can help direct you... - I guess you should call tech support and ask where you adjust this
Michael Jahn - Slightly used PDF Evangelist
Simi Valley California