I also note that the help notes with the software get the X and Y mixed up, stating X is offset from top of page and Y is from left which is incorrect.
Even just printing onto a label sheet I can't get the printed output to align correctly. It's as though the software is clashing with the disk print tray setup, almost as though the edge offset is for a whole print page rather than the disk tray. I have adjusted edge distances but without managing to get near to a correct alignment, likewise the centre offsets. However, using the newly bought Disketch Plus software I cannot get the printed label to line up correctly even when I adjust the layout dimensions/parameters.
I have a Canon Pixma 8500 complete with disk printing tray.