Photo Assist is from years ago. It allowed you to create a static photo gallery. The powerGallery is a much better solution. We stopped selling photoassit because of the antiquated technology and inclusion of other static photo gallery solutions with DW.
Gotcha... yeah when I saw FlashNav, I instantly thought of some of those other flash menu extensions that do seem to have a ton of problems implementing them. Not to mention, I make it standard practice to avoid any flash for main elements of my sites to ensure compatibilty with iPad and iPhone.