Toshiba CF35E50 35" TV "comcast picture large" Questions

...Comcast cable. I get a good full picture on about 8 channels and all the others (70 or so) I have a large black square covering the picture except for the outer 2 inches of the screen. The cable ...

...Comcast cable box. It will occasionally go off for no apparent reason and then come back on in about 3-5 minutes. When it returns, it sometimes comes back on perfectly. Most other times it comes back ...