Apple just released iPhone OS 3.1.3 Software Update for the iPhone and iPod touch addressing several bugs as well as fixes for a few security issues.
This update for the iPhone and iPod touch contains bug fixes and improvements, including the following:
– Improves accuracy of reported battery level on iPhone 3GS
– Resolves issue where third-party apps would not launch in some instances
– Fixes bug that may cause an app to crash when using the Japanese Kana keyboard
More detailed information on the changes of this release can be found in this support document.