I am beginning to wonder if the foil is different. I often use foil to line a baking dish when cooking chicken pieces. Somehow the fat seeps through! And I do put it up the sides. I find the best method when baking things in the oven is to use foil lined with baking paper - as in my baked chicken here. Then, it doesn't leak.Sorry, it doesn't work, and Morning Glory agrees with me Unless of course your foil is different to ours