I'm not exactly sure what to tell you Craig. I usually try something different each time I bake these, which isn't all that often. I've had problems before getting the bottom to cook properly. This time, I baked just below the middle of the oven without a stone, and no convection. The bottom came out nice and crispy. That may be the sweet spot in my oven for DS. I don't really like having to put foil on though.