I have a KF42-WE610 that developed the problem with the optical block. At first Sony said it would be covered under extended warranty. When the repairman came out, he confirmed that it was the optical block problem. He didn't think the problem was covered because my screen was purple, not blue.
Long story short, I sent a letter to Sony customer relations via certified mail and enclosed a color photo of my TV screen. The rep that received my case contacted me the same day. He was given a photocopy of my letter and photo so he couldn't see the brilliant (although wrong) colors on the screen. I emailed him the photo and got approval for my replacement less that 24 hrs. later. Sony covered the repair in full and also refunded the original service call that was my out of pocket expense.
A picture is worth 1000 words and a well written certified letter gets attention. My TV was as good as new days before I received the certified letter confirmation.
Sony does stand behind their produts and I will continue to be a customer.