Now that i have upgraded to HD, my tv, when there

now that i have upgraded to HD on my rear projection tv, when there is a lot of white, Ie - Apple/PC commercial or hockey game - my screen will lose the picture and just go blue. then it will come back once the ad is over. For hockey it is almost impossible to watch a game, becuse of the white ice. If I change it to directv "guide", with a smaller picture in the corner of the guide, it plays no problem. So that tells me there is a problem processing the amount of white within the picture.