New iPhone 3GS week 25 - second replacement with a yellow tint on the bottom of the screen. Nevertheless the build quality on this phone is great - perfect buttons, bezel, speaker, etc. I may just keep it and ignore the yellowing at this point unless I can be sure a replacement would be better than this.
I'm in the exact same boat now. I'm convinced at least all the white 32's have it. Sigh....