Hello all, Just bought a Philips 37" Plasma a week ago. Had it mounted on the wall and all seemed fine. I've since noticed that there is a frequent crackling noise coming from the top of the screen. It isnt always there but seems more prominent during adverts. 1.Should i be worried ? 2.What are the ideal settings for optimum viewing ? ( contrast.. etc ) It's not hooked up to sky yet. All advise would be greatly appreciated.