My application downloads JPEG images from the web and save them to the device using UIImageWriteToSavedPhotosAlbum. All works fine except for one issue: when I browse iPhone's photo library with iPhoto, some images have no thumbnails -- an empty dashed rectangle is displayed instead. Those JPEG images application downloads are also generated by my application as a result of processing pictures either taken by device camera or picked from Photo Library. Maybe I need to do something special during image processing that will make thumbnails visible?