First of all, remove the widget and drag it back in from your library.
You probably haven’t checked the box with the number of slides you are using. If you are using 2 photos, click on -Use 2 slides-. If you are using 3, click on -Use 3 slides-.
¿Have you done this step?
Also, the photo sometimes doesn’t render in the workspace but it will render when you preview it. Does this happen?
You can find further instructions in the readme.txt in your zip.