If you’ve jailbroken your iPhone using greenpois0n, Redsn0w then you might have noticed that you’re not able to open some eBooks using the iBooks app.

Comex, member of iPhone Dev team and developer of jailbreaking tools like JailbreakMe and Spirit has figured out what might be causing the problem.

Comex explains:

It seems that before opening a DRMed book, iBooks drops an improperly signed binary, tries to execute it, and if it works concludes that the device is jailbroken and refuses to open the book.

This is what the binary does:

int main() { return 42; }

and you get the following error message:

There is a problem with the configuration of your iPhone. Please restore with iTunes and reinstall iBooks.

This indicates that Apple is preventing DRM eBooks that have been purchased from the iBookstore to be opened from a jailbroken iPhone as an anti-piracy measure.

It is also important to note that it is not a new issue, iBooks always had these anti-piracy measures in place, but earlier jailbreaking methods were able to bypass these checks. However, jailbreaks like greenpois0n are disabling more restrictions, which is resulting in the protection code in iBooks getting triggered.

Unfortunately, in this case it is also preventing users who have legitimately purchased eBooks from the iBookstore from accessing them.

The goods news is that Comex has figured out a way to fix the problem. MuscleNerd of the iPhone Dev Team tweeted:

@comex did an amazingly fast job repairing the damage Apple did to iBooks on JB platforms (fairplayd is next cat&mouse?)

We’ll let you know as soon as the fix for the issue is released so stay tuned here at iPhone Hacks or follow us on Twitter or subscribe to our RSS feed.

Are you having problems using iBooks on your jailbroken iPhone? Please let us know in the comments section below.