Still working to fix isolated problems with its latest iPhone models, Apple is fielding a new report Tuesday from Japan's Ministry of Economy, Trade and Industry, which said there have been new cases of iPods overheating and scorching nearby materials.

While the exact cause of the overheating wasn't cited, there has been a series of overheating of iPods over the past several months allegedly caused by the devices' lithium-ion batteries.

Overheating iPods have also been reported in the United States. In one case last October, an iPod owner in Atlanta said his iPod Nano caught fire in his pocket, destroying the iPod and burning his pants.

Overheating lithium-ion batteries have long plagued some laptop providers including Apple, which along with Dell, Lenovo, Toshiba, and other manufacturers, has issued recalls for batteries manufactured by Sony.

In the latest case involving iPods, the Japanese government has issued a warning alerting iPod Nano owners to be "careful about overheating of the machines," particularly when they are recharging, according to media reports. The Associated Press said Apple's Japanese office did not have an immediate comment on the issue.

In the two most recent incidents of overheating iPods in Japan, paper and a straw mat were scorched. No injuries were reported.

There have been no reports of overheating iPhones, but there has been a series of reports citing connection difficulties by iPhone owners. The difficulties, believed to be related to hardware components, are being addressed by Apple with software updates. Some iPhone users have reported that their phones spontaneously downshift from higher-speed 3G connections to slower EDGE networks.