I had my subscribers images all disappear, but it was because I was messing with the Category Editor. I set my main Subscriber Category to "Act as Members' Category" and all their photos went away!
Fortunately, I back tracked and got things back to "normal."
I never did get my head clear about the logic of "Act as Category." If you click NO it is a title I guess, because if you click YES, you can upload photos to it. So, I have the master "title" and then all my user "categories" (folders) are below that title.
The logic of the new Act as Category tag is explained as: "When set to 'Yes', any uploads to this category will automatically be placed in a sub-category named after the user who uploaded the file."
I'm still CONFUSED!
When is a category NOT a category?