Apple has released a new firmware for their iPhone and iPod touch, which is surprisingly OS 3.1.3 instead of the much anticipated OS 3.2, which was released with the Apple iPad. The new firmware can either be downloaded from one of the links given at the end of the post, or by simply connecting your device (iPhone, iPod touch) to iTunes. It will automatically prompt for the upgrade option, if you want to install the new firmware. Simply choose “Download and Install” for an instant upgrade.

The iPhone OS 3.1.3 firmware has fixed several important issues like accuracy of battery level, third part apps compatibility, few wifi issues, etc.

According to AppleInsider, the OS 3.1.3 has also fixed an issue that would cause the iPhone to not wake up from the sleep, and has also resolved a glitch that could interrupt cellular network services until a restart.

You can download iPhone OS 3.1.3 from the following links:

iPhone 3.1.3 firmware for iPhone 2G
iPhone 3.1.3 firmware for iPhone 3G
iPhone 3.1.3 firmware for iPhone 3GS