20 images and I quickly count 4 duplicates?.... please check your galleries before you upload them. A few dozen images more also wouldn't hurt.
Edit: The re-upload still contains 1 duplicate, it's not easy to miss it.. it even has the same filename, next time you want to upload a set of images; rar all images that you want to upload and then upload the archive, that way you can't possible have duplicates with the same filename!