I got my slideshow in order thanks to help I received here- thanks again to all who offered assistance. It's 521 images. But when I try to Play or Preview, it hangs up at slide 371.. sits for 5 minutes, then times out. So I removed 371 from the show and tried again, and now it hangs at slide 367 (which it was happy with the previous time).
Makes sense to anyone? Just need to finsih this darn thing!!