New iPhone 3GS Running 3.1 - How do I upgrade to 3.1.2 and jailbreak
Just purchased a new 32GB iPhone 3GS. I have service through AT&T. The 4th and 5th numbers of the serial number are 39, which is the old bootrom and should mean untethered jailbreak. However, it's running 3.1. I don't want to update the firmware via iTunes, because I'm sure that will put me on 3.1.3, which I don't want for obvious reasons. I've read about problems with trying to do the shift + restore method to install another firmware, but that iTunes will give an error message saying that the firmware is unsupported by Apple or something.
I'd rather stay on 3.1 and jailbreak than put myself at risk and accidentally upgrade to 3.1.3. Does blackra1n jailbreak 3.1, or only 3.1.2? My iPod Touch 3G is running 3.1.2 and I've jailbroken with no problems, but it was never running 3.1.
Advice? Thanks a lot.