I finally got my HD Receiver/Box/Tuner whatever you call it from the cable company this morning so I can now watch HD Broadcasts (I have standard package right now which includes networks, Discovery & HBO & Showtime- I might upgrade later).

My question for you guys is, while the picture was fantastic, the entire screen was filled up only on Discovery, HBO & Showtime (this was about 11:00 AM) while the network shows including the commercials also had a great picture, there were, though unobtrusive, black bars on the left and right of the picture. I called up the cable company and they said that meant those were non HDTV broadcasts. Are they right? For some reason on the 1081 broadcasts or input I could only change format to HDTV expand and the picture looked too distorted so I reverted back to standard 1081. On a different input on my TV I can do 480 stretch, zoom , expand and about 9 things total but for 1081 input I can only do HDTV standard & expand. Is this all correct or do I need to get a technician to fine tune my TV?

In regards to my DVD, it appears I can only play this on an input that allows 480 not 1081picture. Is this correct?