Having a similar problem so some of the others here. A client wants to have a slide show with over 100 images. I'm finding that up to 100 images I can save and update anything over the slideshow re-sets. (All images in the slide show vanish)
Slideshow works fine with over 100 images offline on my development server. A 100+ slideshow cloned from my development server works fine but I am unable to change any of the settings ie. speed of change.
I have tried in Firefox and Chrome with the same result.
Anyone have any suggestions. The Client is a storyboard artist so having 100+ images in a slide show is rather important.