Big Screen TV is acting funny

[TableTiger1]

Thought BTP could come to the rescue. I have a 50" plasma 720P Samsung. When I watch movies or play Xbox360 the screen has a bunch of little rainbowing pixels all over the screen. It only happens when the movie is loading up or the game is on the main menu screen. When the movie or game is being played everything seems to be fine. The digital cable doesn't seem to do this. I have tried the white out screen feature thinking it was screen burn and it seemed to help a bit but I am not sure. Could it be the cables?

[Marm]