You may have noticed that when you try to open an iBook that you purchased from the iBook Store on your jailbroken iDevice, you get an error saying “There is a problem with the configuration of your iPod touch/iPhone/iPad. Please restore with iTunes and reinstall iBooks.”
What causes it is when you open an iBook that contains DRM, iBooks tries to execute a number of binaries which would only run on a jailbroken device. If any of the binaries runs then it produces the error and stops you from reading your iBook. To perform all this, Apple is using a new tool called fairplayd as shown in the picture below.
This is more likely an attempt to discourage jailbreaking rather than to stop the piracy of eBooks since you can still pirate eBooks even if you are not jailbroken.
This error has been fixed and will be released in an upcoming Cydia package and is currently available in PwnageTool 4.2.
