Probably some problem with the PSIP data for that channel. First, try to do a complete new scan. Some problems aren't fixed by doing just a rescan. Then, recommend you visit the local HDTV forum on this site for your particular market and post your question there. It's possible other people are seeing the same type of problem.
We have a channel where I live that I had to remove from the channel list, because every time I tuned to it, it would corrupt the guide. Fortunately, it is a My Network TV affiliate and there is nothing on there that I want to watch anyway.
Also, there is no way to manually tune to a sub-channel on the Accurian. This is a major negative for this receiver.
Yeah thought that might be the case but I can't add any new channels. They all show up in the channel edit so the receiver recognizes them. Just any changes I do don't get saved when the unit powers off.
I have not watched NBC Channel 7 in a while but yesterday, the HD program from that channel was displayed with huge black borders on four side of the screen. The ABC, CBS and FOX had the usual full size HD picture.