Of course this had to become noticeable while watching the football game in HD. I noticed a slight orange tint on the left and right side of my 57" screen. It is burn-in caused by the black bars (left and right) that appear when watching non HD content.
Here is a link to more information:
If you do not wish to "s t r e t c h" 4:3 content (looks bad IMO) gray bars are better then black. I was able to set my cable box to show grey bars.
Be careful everyone. Burn-in sent my favorite toy on a 3 week trip to the repair center.