Having cause to produce an enormous gallery showing a wide range of my photography, I was stunned to find a transition problem after creating 2 dozen loaders. Initially, I chose 'fade and ease' for transition in the lightbox. Then, I wondered what 'zoom' would look like and changed it. Going to preview page, I found that zoom must be demanding more from my processor than it was comfortable with. All I got from each slide was the black screen and the dreaded spinning wheel. I changed it back to the more comfortable 'fade' but was horrified to find; there was now some confusion going on. Some pictures faded in, occasionally one zoomed and again the spinning wheel. I tried everything to flush what I considered must be some kind of cache problem. Nothing worked. Eventually, after fiddling with it for a couple of hours, the horrifying thought of recreating the entire thing was beginning to take hold. Finally, I decided to go live with it. Uploading the site to the server. It worked, they all now fade with no confusion. I hope I've saved someone a couple of very worrying and frustrating hours.