Apparently fearful of another exploding battery epidemic, the Japanese government has issued a warning and prompted an investigation into recent issues with Apple's iPod Nano. Japan has asked Apple to investigate the causes of several incidents in which the iPod Nano overheated, in a few cases causing fires.

Unsurprisingly, Apple came back with two answers, saying that the incidents were very few and very minor, as well as saying that the cause is bad batteries. Apple also mentioned that the affected units were from a small batch manufacturer upwards of three years ago, and no current generation units pose a problem. They will still be investigating further.