It would seem that some interesting news has come to light regarding the overheating issues with some Xbox 360's. Apparently, modcontrol.com (in conjunction with gamestore24.de and konsole24.de) has found what could be at least a partial cause of overheating in some Xbox 360 consoles. On the GPU heatsink, there is a heat conductive compound that helps transfer the heat from the chip to the heatsink.

From the factory, this compound is covered with a layer of foil to protect it from dust an other contaminants that could reduce the conductivity. It would appear that on many Xbox 360's, this protective foil was never removed when the heatsink was installed, and could be a factor in the overheating issues experienced by many. Many users are now cracking open their consoles (this voids your warranty) and checking their systems, many finding the same problem. Although, it should be noted that some of the poeple that are finding the foil still in place have experienced no overheating problems.