With the lid closed and apple rotated the right way, there is a horizontal semi-transparent black line (~1/4 inch thick), starting ~1.25 inches from the bottom left, and is ~3 inches long. I've tried using glass cleaner but I don't think it is dirt. I wasn't sure about using other types of cleaners (like 409) because I didn't want to damage the plastic. Anyone else seen or heard of this? I'd take picture but the wife has the digital camera.