[Ifeffit] difference spectra function in (D)Athena

Hello Mailing List, I have a question about the difference spectrum function. I chose difference spectrum in norm mu(E) in the Demeter pull down menu. I set the standard and chose another spectrum. Plotting both the difference and spectra gives me the image attached. Is the difference shifted significantly to lower energy? If so, why does it change its energy scale relative to the plotted spectra? Is there a setting I can change or could this be a small bug? Thank you all, buena salud, Chris Patridge -- Christopher J. Patridge PhD. Contact: (315)-529-0501