I tend to notice in very dark room like at night without any light on. On black screens you can either look on a AV channel with noting turned on for that AV channel to get the black screen is that i see a light shadow at the top of the screen like the rest of the screen is black but at the top it like someone shining a Dull tourch or somthing. Hard to explain reall. I rang the sony helpline and they told me it appears on alot of Flat screen tvs 100hz. They say there no guarantee that it can be cure without effecting the picture size of somthing. I am calling for kv32fx66 users or some sony users just incase it appears on other modle to look at there tv at night time in a dark room nothing else turn on int he room you know when it dark outside aswell. Is to look at your set and see if you have it.