A faulty batch of DS Lite chargers in Japan have been recalled by Nintendo after an overheating issue has raised safety concerns.
A statement on Nintendo's Japanese site identifies the batch of power cables affected, and calls for them all to be returned, with a replacement sent to everyone affected.
No serious malfunctions or incidents have been reported, so we assume this is simply a precaution taken by Nintendo. It has been confirmed that these issues do not affect European and US territories.