I bought my Samsung 50" 720p 600Hz Plasma HDTV PN50C450 brand new less than 2 months ago. It is a great TV and has an amazing picture for the price. However, every so often- the picture dims slightly, then immediately brightens. When it happens it will occur every few minutes for maybe 15-20 mins. It may not happen again for a week. Is this a power issue or is it something seriously wrong with my TV?? I know nothing about TV's and have not been able to find information on this problem anywhere on the internet. Any advice would be greatly appreciated.