Just a quick heads-up: the iPhone DevTeam has updated redsn0w to v0.9.10b4 to incorporate the 5.0.1 fix for iBooks, and also for sporadic problems with launchctl. As usual, you can choose to install the fix either by re-running redsn0w over your existing jailbreak (de-select Cydia if you do that), or by installing the corona package from Cydia (it’s the same set of files no matter which way you choose). TIP: If auto-detection fails and redsn0w tells you no identifying data was found, you can always pre-select the appropriate 5.0.1 IPSW using “Extras->Select IPSW”.

Here are the redsn0w download links: