Since a recent sofware update from sky,there have been many situations of the pin number been asked for when going to "other channels".usually its the last 4 numbers of the card number,if its the original card married to the digibox.Sometimes it doesnt work so you have to call sky.But if its not the original card eg a FTA card from elsewhere then there is obviously a problem.One trick I tried is to take the card out and power off the digibox then on again.Then when it says "insert card" put card back in and then it should be back to normal.Another way i read on satcure,but not tried is to activate the age restriction(as this requires a pin code) then de-activate it.