We have an Oyster Dish and had a small GM box fitted that takes the Sky card and it works. we only have the basic sky package. When we went away for 3 months this winter, after a few weeks the card stopped working, we also met a couple who saw our dish up and asked us if we could get any sky programmes as their card had also stopped working. We were only in France at this time. When we arrived home we had no Sky TV and had to contact Sky. They said that the box had to be left on with the card in as they needed to communicate i.e, send signals to the box/card. After complaining about it on the Sky Forum, I was told that Sky are now sending what is known as a keep alive signal to the sky card. A signal is sent with a certain amont of viewing time, I dont know how much,shortly before that time expires another signal is sent with another period of viewing time, and so on. Si it seems if you want to watch sky you will have to take your box from home which needs mains power.