Using my cablecard I am unable to tune into 553. It is the only channel I have noticed this on. If I tune to 552 or 554 I get HD quality and my CableCard (CC) menu says Authorization = subscribed. If I tune to NHL Network HD (which I don't subscribe to) the CC menu says Authorization = not-subscribed. If I tune 553 I get an Authorization = unspecified. 553 does work on my other HD Motorola box though. And SD 53 works with the CC.