when making some modifications of images (Ctrl+U), you can select "delete original". When performing action, XnMP warns you of your choice (and this is great compare to XNV) but it you chose not to change the name, XnMP asks you for each file if you want to replace the original file by the new one. If I chose "delete the original" it is obvious I do not want to keep the original
What a dumb program 