I have a Hitachi Ultravision 50" RPTV. My cleaning lady used some sort of cleaner on the screen. Anyway, she didn't use it on the whole screen- in other words, she cleaned in a circular motion not touching the four corners of my screen. Here is the problem, when something light comes on the screen (looking at the ice when watching a hockey game) you can see a discloration circle on my screen. The corners look a shade brighter than the rest of the screen. What should I use to clean the screen now? Is soap and water OK? How much to replace the screen? Thx.