Hit iTunes for your fresh copy of iPhone 3.1.3 (Build 7E18) which weighs in a 228.1MB. The update “Improves accuracy of reported battery level on iPhone 3GS” and “Resolves issue where third-party apps would not launch in some instances”.
Update: We’ve found that Apple has updated the Modem Firmware from version 5.11.07 to 5.12.01 on the iPhone 3G.
That means there is likely some more stuff going on behind the scenes – as per usual. Therefore, Jailbreakers are advising not to do the update.
Has anyone out there found any undocumented features/snappiness