After being updated this morning to fix the DRM issues in iBooks, as well as Redsn0w, Saurik has tweeted that this jailbreak has been updated once more. This time it’s to resolve problems with the well-known, iPhone 4s.
If you are having trouble with your iBooks on your device, you can simply install Corona from Cydia. If you have installed it previously and want the update, just update it via Cydia.