Apple released version 3.1.3 for its iPhone OS software for iPhone and iPod touch. The update can mainly solve the following problems:

Improves the accuracy of reported battery level on the iPhone 3Gs.

Resolves an issue where third-party applications would not launch in some instances.

Addresses a bug that could cause applications to crash when using the Japanese Kana keyboard.

Meanwhile, the baseband will be updated.

The update is available to download via iTunes and weights in at around 300 MB. It is important to note that the update is not available for jailbroken iPhone / iPod Touch. There isn’t a jailbreak/unlock for this firmware yet.