I have sky+ and set up the parent control with pin number from the last sky card, which used to be the last 4 digits of the number on it.
Received my new card some months back and only now do I need it to watch a film.
When asking for the pin now it is not the last 4 digits on the new card and I can't remember what the old one was.
I have not had the phone line connected since the new card was put in.
In short apart from phoning the number that comes up for sky is there a way of resetting the number, long shot but if you don't ask.....