After editing an image, I save the image (not in the same set), replacing the original. When I do this, it saves two copies of the same image. Why?
Please see if this option on Save dialog is UnChecked while you are Saving and you are saving in same format as original.
Hope this helps.
When I saved the edited image, I left the 'as a copy' box unchecked, but it still made a duplicate. It does this every time which is really annoying.
Please state your OS version. Seems specific to Apple.
I have left the Save box unchecked, and it still creates a duplicate. In your screen shot, I see you have also left 'Include in the Elements Organizer' unchecked. Is that correct?