@creedon
Realized what was the problem. My png images in Gallery -Slideshow mode had a light grey background to it and was not transparent. I realized in the design menu, if you select the "Automatically Crop Images" The "Transparent Background Check box" Disappears. If you deselect it reappears at the bottom of the menu. They should fix that. Or allow transparent backgrounds while allowing cropping. They should at least display the Transparent Background option, but grey it out - or provide an explaination as to why one can't use Transparent background in Cropping mode... Please fix this Squarespace. It took me months just to figure this out....