So the iPhone Dev-Team has gone through with the launch of beta 1 and beta 2 of the new Redsn0w version 0.9.7 through which you can untether your iOS 4.2.1 jailbreak on your iPhone 4, iPod touch and iPad, however, beta 1 had certain bugs, like the crashing of native apps after the jailbreak had been done, making those apps unusable. However, this particular problem was fixed in beta 2, and now, the team has, quietly as they claim, released beta 3 of Redsn0w 0.9.7, which fixes bugs regarding non-GUI programs which handle media content. More details given below.
This is what the iPhone Dev-Team has to say about the beta 3 of Redsn0w 0.9.7 over at their blog:
The third beta is now available (testers ONLY please!). This version extends the fix made in beta2 over to the non-GUI programs too (like the daemons that handle media content). That should cover things like Facetime, Winterboard themes, and embedded videos in iTunes. If you had trouble using the usbmuxd in previous betas, please wait until we incorporate that into redsn0w itself (i.e. don’t bother trying this beta3, just wait for the integration).
However, it should be kept in mind that the actual jailbreak untether method does not change in any way, and it should also be strictly noted that the previous warnings that were given out, particularly for this test program before the general release, also remain the same.
Download Redsn0w 0.9.7b3 from here.