I recently resurrected by ten year old Morphy Richards Quick Bake breadmaker, and there are black metallic streaks in the bread. Yuck! It's coming off the stirry-kneady thing and off the tin itself I think. Anyone know if you can buy just tins, or does the whole thing need replacing? I have finally mastered the art of baking a passable loaf in it, so don't really want to start over with a new one - it's about the only thing I can bake