Each release of iPhone OS usually results in the iPhone Dev Team (not to be confused with actual Apple engineers) going back to the drawing board to re-enable jailbreaking, which lets iPhone users install unofficial software and access the UNIX-y internals of the operating system. However, Apple looks to be stepping up its fight against that practice, as iPhone 3GS models coming off the assembly line recently apparently have new bootloader code designed to make them jailbreak-resistant.

"MuscleNerd" from the iPhone Dev Team has confirmed that Apple has updated the version of iBoot on the latest iPhone 3GS to 359.3.2. This version isn't vulnerable to the "24kpwn" exploit that has been at the heart of many jailbreaks, which could bypass part of the usual boot process, and allow unsigned code to run on the iPhone's processor. This means that even the latest version of PwnageTool, which can jailbreak iPhone OS 3.1.2, can't jailbreak these devices.