I have been doing some pens plots on Mylar (drafting film) that required a very high level of detail (within +/-.01 or so). In doing so, I found that the cutter wasn't exactly running true to full accuracy. I found that there is a calibration sequence that allows you to fine tune the accuracy. After doing so, the plots came out fine. Here's the BUT...seems like the machine would not consistently hold the calibration information or something. I did these plots over several weeks, and also noticed that some cut vinyl with reg marks was not lining up right (on the order of like 1/8" or better off). This only occurs in the Y or running direction, not the X or side-to-side direction. I of course called Tech Support and they said that once calibrated, that the settings should stay. Now, has anyone else came across this and if so, is there some other setting either on the cutter on in the Cutter Control software that controls this? Any help is certainly appreciated.