I just talked to Aria in Kindle CS and did you guys know it's the users causing the problem. They've "researched the problem" and when this happens it's screen damage from people holding the Kindle by the screen and breaking it or damaging it by trying to use a stylus on it.
So apparently the sun problem is now imaginary. I'm sure this is just her not understanding the actual issue because when I asked how the screen could go back to normal after being out of the sun if it was broken she didn't know what to say.
Anyway, mine has a slight problem like this (nothing like the OP's) and I'd have actually been fine keeping it, but mine's being replaced because the longest the battery will hold a charge is about 36 hours with Whispernet turned off. I hope the new one doesn't have a big case of this "non existent" screen problem.
All in all I do have to say that my experience with CS was nothing but pleasant though.