No this is not in regards to clouding, or when the picture is completely dark and involving the 4 corners of the set.
I'm talking about the top row of LED backlights along the top of the set, mainly towards the middle of the screen, but really the whole top row suffers from this.
When the image on the screen is bright/white/colorful and especially when moving or panning horizontally, the individual rows of LED backlights along the top edge of the set (being that the set is "Edge Lit") increase substantially in brightness to the point where you can literally see the individual beams of light shinning down vertically across the image, almose creating a wave of uneven lighting along the picture. In darker scenes this is not an issue. Each LED back light is about an inch thick (in brightness) and spaced about 2-3 inches apart. I know this for fact due to my TVs defect.
Somebody else has to have been suffering from this. My set is a KDL-46HX750 but I'm sure its not model specific. Sony wont hear anything of it and keeps dismissing it as clouding issue.