Hi, I have a new comcast account and am paying for HDTV (basic channels). A friend gave me a comcast motorola hd dvr box and I want to use it with my current account. The box will only receive a few local hd channels and not the rest. I think comcast has the serial number of the box registered as invalid. Is there a way to reactivate this box so I get all the channels I am paying for on my regular non-drv hd box? Thanks.