If you can, check your TV has its latest firmware and if you can't, just make the call to ask how to check and update then get into this issue with the maker.
I have a LG UJ6300, and when I'm watching a movie or a TV show where the screen goes black -- for instance, between title cards during a credit sequence -- the display does this maddening thing where the backlight seems to go out and the screen dims, thus shuddering between these two black levels. It's almost like the screen is going to sleep when it doesn't detect anything on it. Does anyone know a way of turning this off? At first I thought it was an energy saver function of some kind, but that doesn't appear to be the case. Thanks!