Darkslide 1.5.0 pro doesn't retain/respect upload compression

As I understand it the "upload compression" setting should mean how pictures are resized or recompressed (e.g. JPG compression level) or both before upload to save on bandwidth and accelerate upload. However so far the upload compression setting always resets to "none" and doesn't seem to affect any upload even if selected immediately before uploading. Also while the upload page says that photos from camera roll are always resized to 640x480 in my experience they were uploaded in full size (pixels as well as bytes).