1) My computer OS is Windows 8.0 (64 bit)
2) A sheet of labels is 8 1/2" x 11", 2 labels to a sheet.
3) Yes, the labels would fall within a .25" margin.
The area bing misprinted is horizontal rows (portrait orientation of the labels) on print larger than approximately 12-point font. This seems to happening when I print from a website, such as USPS, Etsy and Amazon. Everything is fine if I save the labels to my computer, then print from Acrobat.