has just released an update to fix iBooks Redsn0w
to make untethered jailbreak OS 5.0.1 iPhone 4 and iPod Touch , iPad.
Update: MuscleNerd of iPhone Dev-Team has just updated Redsn0w for both Windows and Mac to version 0.9.10b4 which incorporates the above fix for both iBooks and launchd. The fix can be installed by simply re-running (uncheck Cydia option) this new version of Redsn0w over the existing jailbreak.
redsn0w 0.9.10b4 Windows
redsn0w 0.9.10b4 MAC