I just got the same TV a couple of weeks ago. I'm noticing the discoloration but only when the screen is black- if that makes sense. When I'm watching a movie I don't notice it much so I'm not worried about it for now. I'll keep a close eye on it, if it gets worse there's always the warranty...
I just got a new Sony wega and I'm trying to set it up using the Avia Dvd. I'm having difficulty with the first set up (picture/contrast). They talk about the boxes in the top of the picture blooming when it is set too high. Maybe it just me but I don't see any blooming even when it's turned up...