I think it's the bootm frmae border of the image window, but I'm not sure. I did find a forum support link that mentioned this, but I'm not totally sure on this one. It is olny happening to about (6) of my 80 or so products. It's on a coulpe of the boot products. I've spent a few hours recreating the products from scratch and recreating the images, but it's still the same?
Here's a link;