Has anyone else developed blemishes on their HTC desire [Or other model] camera window in the rear cover?

While the glass itself isn't scratched, there seems to be funny patterns within the glass layers [as it isn't on the inside or outside of the glass] with a slight rainbow effect like soapy water was left to dry streaky.

I was hoping the glass had some kind of shipping plastic over it that could be peeled off but it doesn't seem to have.

Wonder if i can replace it as it does effect the quality of my photos?

DLS