I hate to tell you, but Toshiba gave you a line of bull. They are trying to get you to waste time until your warr expires. You have a panel that is progressivly getting worse. This is not isolated to your set and is common on all makes and models of flat screens. If you are still in warr, contact a servicer and show proof of purchase and you will get your set fixed. If it is out of Warr then I am sorry, it will be cheaper to by a new set.