SD recordings on an HD channel have been upscaled to Hi-Def. By the time they hit your house they are hi-def from a bit rate perspective. The PocketDish just can't handle it.
Current generation PocketDish can't handle h.264 either. So, expect more trouble if Dish ever starts converting SD to mpeg4 (probably still a few years away).
David,
First SD recordings on HD channels are NOT be scaled up to HD. The actual resolution for HD is either there or it isn't. Most HD TV series are recorded on 35mm film which is higher resolution than HD. The film master is then remastered to either 1080i or 720p and then broadcast. SD content is NOT upscaled into HD, SD content (720x480) can be scaled to be broadcast in a 1080i or 720p format but the results are simply NOT pretty. Garbage in equals garbage OUT. You simply can't start with 1/4 of all of the HD pixels missing and expect even decent results when upscaling SD into quasi HD.
High Bit rate does NOT mean a channel is HD or SD. A HD channel using MPEG4 compression results in bit rates that are about half of the bit rate for the same channel using MPEG2, but the resulting PQ is the same. Again a High Bit rate means little to nothing if that Bit Rate can't resolve a great picture, the efficiency of the modulation scheme (8PSK, QPSK), as well as the efficiency of the Compression scheme has a lot to do and it some cases MORE to do with PQ, than a RAW measurement of a Channels Bit Rate.
High Bit rates just mean more used BYTES of storage, Dish has purposely disabled the PocketDish's ability to store HD programing, specifically the result of the Content owners DEMAND that they do so.
The Pocketdishs' inability to store HD programing is the result of this demand, and less about the technology involved.
John