Discolored Bands on the Side of Widescreen Projection TV?

Question

I have a widescreen rear projection HDTV. I think it is 36-40 inches wide and it is made by GE. The screen is three or four years old now and most of the time we have run the screen in a 4:3 format (other formats are 16:9, cinerama, extended 16:9, etc.) and when it is run in this format it has two light grey bands on the sides which fill the area the "standard" image does not fill on the widescreen. Now when we turn the TV to another format that fills the screen the sides (where the grey bands reside in 4:3 mode) are discolored. Earlier it was just noticeable when blacks where shown in that area, but now it has gotten bad enough that it can be easily noticed at all times. Does anyone know/have any ideas on a) what the cause is and/or b) how to fix it?

Answer 1

This happened to my parents tv, but they were getting blue discoloration. It slowly got worse and worse until you could hardly see the tv. It turned out that the colour tube or something had burnt out, and it cost about $1200 to fix.

How old is it? Is it under warranty.