Let me know if this is not an appropriate place for this question since it is not about a particular show, but a more general question... I'm new to HDTV. I've had a capable TV for about 3 years, but have only recently upgraded from basic cable to the digital package that includes several HDTV stations. I've noticed something every once in a while that I'm curious about. Periodically, with a program that is supposed to be broadcast in HDTV (the "available in HD" or "HT sponsored by..." blurb comes on at the beginning), it will alternate between a widescreen HD presentation, and a pillarboxed 4X3 presentation. For instance, the first episode of House this season started out pillarboxed, and after the first commercial break the rest of the episode was widescreen HD. On the first episode of Night Stalker, it was all widescreen HD, except after returning from one commercial break, it was pillarboxed for about 2 minutes and then returned to widescreen. Why does this happen? Is this a problem with my network affiliate? Or a problem with my cable provider? By the way, I recall this happening only with our ABC and FOX stations. I believe all the other HD stations have broadcast as expected. This leads me to believe it is a problem with the affiliates, but I'm still curious about "Why?"!