Signed up with the forum to discuss this issue. Ordered my first Vizio in January and returned it to the store the following month. It was initially perfect, but developed issues with the backlight after the first several weeks. I blamed myself because I noticed inconsistent lighting some time after wiping down the screen with a microfiber cloth...perhaps I applied too much pressure. Second TV purchased in February was also perfect initially until I noticed the white spots over the weekend. Googling issues with this model brought me here to discover it was a common problem. The second TV also developed a more pronounced flashlighting effect along the bottom edge after about 90 days. I could deal with the still relatively minor flashlighting, but not the white spots...once I spot them and I know they are there I am constantly looking for them.
Being early July, my 90 day return policy had expired at the store where I originally purchased the TV back in February, but a call to their corporate office requesting an exchange led to a store manager calling back and offering to override their policy. Major kudos for this and I will be following up with their headquarters to let them know. They didn't even make me try dealing with the manufacturer first. Installed the third TV last night and thankfully no issues with the picture even on full black/blue/white screens. Hoping for the best, but I confirmed I have another 90 day return policy with this one as well.
My theory, which I welcome other opinions on, is that these issues may develop from too much contact with the screen. I didn't touch the second screen at all following my issue with the first TV, but I found out my girlfriend would occasionally wipe the screen down with those Windex electronic wipes while cleaning. Perhaps too much pressure or a small amount of moisture could lead to these issues? Either way, we both have our fingers crossed and it's hands off with this screen!