I have a Roland GX640 and all of a sudden on print and cut jobs the plotter is starting to miss-cut. It starts out fine and then as it goes it cuts higher and higher off of where it should be cutting. This has happened on multiple jobs with different materials and I can't seem to figure it out. I looked over my rollers and they all seem fine. I've tried running the calibration from the service manual and everything looks good there which I believe that is more for the left/right calibration - is there a separate calibration for the feed does anyone know? or a setting or something I am missing somewhere that could be causing this...?