Hi valsgirl
I have to be honest, the picture problem you described does not fit with any video/ backlight artifact I know of. Does it persist when you're using the internal tuner to watch Freeview? Is it only on certain or all programmes? With the DVD (man with glasses) perhaps what you're describing is deinterlacing artifacts (twitter, moire, jaggies), in which case try using [Film Mode] "Standard" for movies, and [Film Mode] "Off" for video material.
Warmest regards
Vincent