I understand, sort of, how a convection oven works and that it's supposed to save time, but I just roast a small chicken in a porcelain dish with the convection roast setting and it didn't quite work the way I wanted. I cooked the chicken breast side up and the top of the bird cooked very nicely, thank you, but the back (bottom) was underdone at the same time. Do you have to roast things on a rack when you use convection roast? Would using a rack have made a difference? Any advice is most welcome.