Dark areas of samsung LN32B650 picture are black at turnon

Samsung model LN32B650 LCD tv: Immediately after being turned on the areas in thpicture that are supposed to be a dark color are solid black. At every startup of the TV, ater running and warming up for a while, the picture will sudenly "self correct" and with all colors and brightness/darkness levels being correct. These warmup times vary in length from under a minute to much as apporximately 15 minutes.