Win7-64 Ultimate, DisplayFusion Pro 9.7.1 (now)

Ever since I installed DisplayFusion a year or so ago, I cannot change the wallpaper by any means. I have a pure black desktop (which is fine by me), but I cannot change it. I want to replace the calendar bmp I use for each month in the center.

I've tried the standard methods of changing it, every option in DisplayFusion, and every relevant suggestion in the discussion search (though I do not have some of the registry keys mentioned). The group policy items are all Not Configured.

I can see the image on the Windows Lock Screen section in DisplayFusion when the box is ticked for Use the current Desktop Wallpaper image for the Windows Lock Screen, but that desktop wallpaper image is never seen as wallpaper.

Baffling