Downloading topo maps with USAPhotoMaps

Hello All,After downloading a batch of map sections and using BigJpeg, when I try to create the JPG and JGW files I invariably get the message that a file(s) is missing. It or them are always in the upper and/or lower horizontal rows of map sections. I think they are the first and last map section files. So far I've been able to obtain a JPG by setting the BigJpeg boundaries to eliminate the upper and/or the lower rows of map sections. Has anyone else experienced this "problem"?Wil