Hi Ray,
Oh, this changes things a bit. What is the make and model of the cable box on your upstairs TV, and on the downstairs TV? Is the downstairs HDTV the same as the Panasonic plasma? What type is it? If it's LCD rather than plasma, then you might be getting some motion artifacts from the LCD.
Also, cables boxes are cranked out by the millions with, in my experience, relatively poor quality control. I've had to exchange my Scientific Atlanta Explorer 8300HD twice because of various problems. My current one seems excellent and has been trouble-free.
Are you using different outputs from each box? Component or HDMI? Try substituting the upstairs "good box" for the one downstairs and see if the video artifacts go away. Make sure you use the same outputs, otherwise you're comparing apples and oranges.
Regards,
Alan
