RedSn0w 0.9 is officially out of beta and is now available to everyone who wants to jailbreak iPhone 3.1.2. RedSn0w had been in beta testing for a couple of weeks now and the Dev Team worked on fixing the bugs. Apparently, this release is now completely bulletproof.
This release of RedSn0w supports all iPhone and iPod Touch models (still a tethered-only JB for late-model devices though) and runs fine on Windows and Mac OSX.
I was a little confused about the baseband situation so I asked MuscleNerd directly. Here is what he has to say:
redsn0w itself doesn’t update the firmware, or the baseband. It just works with whatever firmware is there and ignores the baseband. redsn0w happens to know about both 3.0 and 3.1.2 firmwares, so it can jailbreak (or add logos, etc) to either.
ultrasn0w right now is only for baseband 04.26. If you have baseband 04.26 on 3.0 (which you normally would at that FW version), then that works fine for ultrasn0w. If you have baseband 04.26 on 3.1.2 (you got there through a custom IPSW), then that works fine for ultrasn0w too. And in both cases, redsn0w can be used to jailbreak, get Cydia, and install ultrasn0w.
However if you somehow have baseband 05.11 on firmware 3.0 (you went up to 3.1.2 then tried to come back down), ultrasn0w won’t do the unlock, even though redsn0w will work fine. And if you have baseband 05.11 on firmware 3.1.2 (you did a stock apple restore/update), then ultrasn0w won’t work there either.
I recently wrote a tutorial on how to use RedSn0w to jailbreak iPhone 3.1.2. Check it out if you want to jailbreak your iPhone using RedSn0w, which you can get from our iPhone downloads page.