If you’re a regular jailbreaker, you’ll be happy to know that iOS 4.2.1 is jailbroken already and that you can download the IPSW and roll your own install immediately. RedmondPie has a great how-to but it’s pretty simple.
iTB: How to Fix Missing keys.plist Error while Jailbreaking iOS 6.0.1 Complete Guide
Glad you figured this out! It shouldn't be this hard to get redsn0w to work; we'll ask MuscleNerd to look into this and hopefully figure out a fix for future versions of redsn0w.
Think iOS - iOS hacker MuscleNerd has confirmed via Twitter that the newly released iOS 5.1 can be tethered jailbreaked using RedSn0w on non A5 iOS devices. Thanks to geohot’s limera1n exploit users with devices prior to iPad 2 and iPhone 4S can simply jailbreak there iOS 5.1 running devices using RedSn0w 0.910b6.
RedmondPiew - According to MuscleNerd, a prominent member of the iPhone Dev Team, iOS 5 Beta 3, which was released to Apple developers a few hours ago, can be jailbroken using the same version of Redsn0w that was used for iOS 5 Beta 1 and Beta 2.
