Non homogeneous light: a possible cause

Hey everybody,

So I finally cracked my kindle open for practice (I'm ordering a replacement battery).
Disassembling and assembling it went well, excep that after a while the frame is closed - I'm talking about tenth of minutes - the screen gets some dark spot in the lower part.
This is a problem the kindle has always had, including mine. The darker spot just changed position after opening the kindle, so I opened it and gave another look.

I have noticed that in the lower border of the frame, right where the leds are, there a thin milk-white strip of... glossy paper, it seems to me.

I think THAT is the cause of the non homogeneous lighting. At a closer look, actually, you can see that it is not glued to the frame, and that it has some... I'd say "bumps". It is that, I think, that causes the darker spot.

I was wondering... what happens if I remove it? The light might stop being effective? I think it acts more or less as a mirror, but I don't know. Has anyone tried to remove it?
My alternative would be to glue the paper more effectively to the frame.

Please let me know!