@mlaverdiere I would appreciate an update on your findings. There is no issue more serious than file corruption. If you can replicate the problem, it could be caused by hardware or software. It’s important for the community of Rapid Photo Downloader users (and me as the developer) to know which is the case in the problem you are seeing.
I really truly don’t have time right now to go into details of why actual file verification is not an easy problem to solve. The only way I know of to truly be sure a file is copied correctly would be to copy it onto 3 different systems and then compare the results, taking the results of 2 of them when 1 differs. If all photo file formats had a checksum built into them, that would make life easier. Alas, they do not.