I am running the latest build 4.4 of Fotomagico and the audio is super low when I try to run it as an application. I can playback full screen and the audio is normal volume. Not sure if this is a bug or how to fix this.
Most likely you have used your scroll wheel on your mouse (or a two-finger-scroll-gesture on the magic mouse) to turn the volume down accidentally while playing back a slideshow. The Standalone-Player will keep the audio volume setting even after restart. To fix this, you have to run your Standalone-Player and turn up the volume by using the scroll wheel of the mouse.