to clarify:
I was mixing up "gallery" and "garage" so my comment may be off base for the original question. I actually did not try to put pics in the gallery, I was trying to put my car in the "garage". When I tried that multiple times it said I already had the max number allowed, but in fact I had nothing in there. I think I see people with cars in the garage that aren't contributors so that's probably not really the answer. But for some reason the contribution thing worked for me, plus it's a good cause, and now I see the screen about adding cars to my garage whereas previously I could never get that far.