Last week Apple updated its bookstore and reading app, iBooks. Among the changes is the ability to detect jailbroken iPhones.

[ad#Google Adsense 300×250 in story]According to a post on MacRumors on Tuesday, users of jailbroken iPhones that installed iBooks 1.2.1 are met with the following message when they try to open content purchased from iBooks: “There is a problem with the configuration of your iPhone. Please restore with iTunes and reinstall iBooks.”

Of course, reinstalling iBooks won’t do any good because the phone itself is jailbroken. However, the app will work properly if the iPhone is restored using iTunes, which brings the phone back into compliance with Apple’s policies.

iPhones that have not been jailbroken apparently do not have the problem.