Hi - if you have Sky in the sitting room and the the bedroom, I assume that you have a multi-room subscription. Our friends had the same problem happen when they stopped connecting the box to the main phone line. Apparently, it needs to stay connected all of the time for you to keep your service.
Don't know if that is the problem, but I know that the connection isn't lost straight away when you unplug the phone line. It takes a couple of weeks before Sky pull the signal to the second TV.