Some early adopters of Apple's iPhone 3GS are reporting that the shiny white back of their handsets is changing colour after intensive use.

Users have reported the issue on several sites, including AppleInsider, and posted images of their white iPhones turning brown and pink on the back. They all report the colour changes occurred after prolognued, intensive use, such as playing games, navigating with GPS and using 3G data. Punters speculate the new CPU is a bit too hot for the old chassis, and that the excess heat gives the tasty pearl white back a crunchy, brown crust.

Another culprit could be the battery, as some users report the colour shift outlines the power pack. The old 3G model did not have such issues, and the black 3GS doesn't seem to be changing colour either, although it gets just as hot under load.

Apple reacted to the reports by closing the discussion thread on its forum. Smooth.

More here.