I was having trouble with my slide shows repeating and jumping all over the place. After looking at this for more than an hour I realized the program is running as developed and there are two areas that can cause confusion.
1. If you have the display order for a Category set as Random, the slide show just isn't going to give you anything reliable for output. No wonder it has difficulty - the next slide is random, repeatable and it may take a long time or no time at all to reach the "last" slide.
2. Since you unfortunately can't pick a slide show until you pick a single slide, you may not notice that you might change locations when you select that slide. For example, if you are in a Member Gallery and you select the first slide which happens to also be posted in a Category, the slide show will start in that Category. You'll see the first slide as expected and after that you'll be surprised. So, look carefully when you start a slide show in a member Gallery.