It wont be long before some newer apps from the iTunes App Store will require you to have the latest iPhone 3.1.3 firmware in order to install a particular app. Earlier this month, Apple released the new iPhone OS 3.1.3 for iPhone and iPod touch which upgraded the baseband to 05.12.01 for iPhone 3G and iPhone 3GS, hence making it impossible to unlock them on the latest firmware with the newer baseband.
The newly released iPhone 3.1.3 firmware for iPhone and iPod touch updates baseband to 05.12.01 on iPhone 3GS and iPhone 3G, hence making it impossible for these two devices to get unlocked using blackra1n with blacksn0w. Fortunately for iPhone 2G (the first generation iPhone with EDGE) users, the baseband remains intact. The iPhone DevTeam has just confirmed that their newly released jailbreaking tool called redsn0w 0.9.3 can be used to jailbreak and unlock iPhone 2G on firmware 3.1.3, provided that you have jailbroken it previously at least once.
After releasing an update to iTunes (version 9.0.3) yesterday, Apple today has announced the new iPhone 3.1.3 Firmware for iPhone 2G, iPhone 3G, iPhone 3GS and iPod touch. One thing which is to be noted here is that this isn't the same version which runs on the newly release Apple iPad (OS 3.2). If you currently rely on your unlock for iPhone 3G and 3GS, we highly recommend you not to upgrade to this new iPhone OS 3.1.3 unless and until new tools are made available from the likes of George Hotz and the infamous iPhone DevTeam. Upgrading to iPhone OS 3.1.3 now may result in your device getting potentially locked forever.