It looks like there may be a little discrepancy between the area selected in the "preview" and the actual area scanned. I usually scan a bigger area and then crop the scan down to the final size. It does make it a two step process though. I usually scan several chips at one time - well separated on the scanner - then use the image editor (like Photo Shop) to crop it down to an individual chip, use the "Save As" save it, and then do an "Undo Crop" to bring the full scan back up and move on to the next chip.