Although the iPhone Dev Team has had this warning
issued for quite a while, it seems that many 3GS users have made mistakes along the way of updating to firmware 3.1.3, possibly losing their carrier unlock, and ability to jailbreak, forever. Softpedia does not condone these hacks.
to the infamous group of hackers, only
those who have their “SHSH hashes” backed up via Cydia should attempt to jailbreak their iPhone 3GS on firmware 3.1.3 using PwnageTool 3.1.5. “iPhone 3G and 3GS unlockers should always be very wary to update their firmware. This is no exception. If you make a mistake along the way you may find yourself updating to official 3.1.3 in which case you will lose your unlock, possibly forever,” the iPhone Dev Team says.
The hackers delve deeper into the subject, explaining that, “iPhone 3GS users (regardless of unlock) should stay away from [PwnageTool 3.1.5] and all 3.1.3 jailbreak tools unless you know you have your ‘SHSH hashes’ backed up via Cydia. That’s because if you make a mistake you may find yourself stuck at official 3.1.3 with no way to jailbreak or come back down to 3.1.2 to jailbreak.”
“If you really truly feel that you need to update,” the Dev Team stresses, “this version [of PwnageTool] creates a custom 3.1.3 IPSW for you to restore to on your iPhone 2G, iPhone 3G, iPhone 3GS with early bootrom, iPod touch 1G, and iPod touch 2G with early bootrom. If you don’t know if you have an early bootrom or not, please avoid updating until you learn more.” Softpedia doesn't condone jailbreaking / unlocking the iPhone / iPod touch or any other device. This article has a purely informational purpose and doesn't, in any way, suggest that you should hack your Apple device. Using hacks may render your device unusable, or may reduce the quality of your experience employing the respective device. If you choose to download and install jailbreak tools, you will do so at your own risk. Unlocking / jailbreaking your iPhone / iPod touch may violate your warranty or the EULA with Apple and / or your cellular-service provider.