[Millay]

Forgive me if I am wrong but my knowledge on this matter is not great. but the reason this would only affect your set top box and not your tv etc is they both use different forms of infrared to control each other.

TV's etc use a very simple for of infrared that only allows simple commands.

Sky NTL etc use irDA, this is a form of transfering data between devices (often seen in mobile phones and laptops etc. this is a more complex technology that can transfer data rather tahn simple light beams.

Thats why ya telly etc don't get confused, you could say it uses a dumb form of command!