I think my slow-cooker is too quick Even if left on low, a dish will be cooked in about 6 hours and will start to stick around the edges soon after that. So I'm worried to leave it all day in case it burns. Surely the point of them is that you can go out at 8am and come home at 7pm and have dinner waiting for you. Are they not designed to be left on for that long or is it just mine?!