@comex really did fix the iBooks issue, with a .deb file and you don't even have to restore/re-JB
Step 1 : Download the deb.File
Step 2 : SSH the deb.File to ur iDevice
Step 3 : Open iFile on ur Device and install the deb.File
Step 4 : Respring ur Device
Get Honnypot via Cydia
Step 1: Launch Cydia >> Manage >> Source >> Edit >> Add >> type – http://cydia.machackpc.com >> Add Source >> Done
Step 2: Tap on MacHackPC Community Repository
Step 3: Tap on honnypot
Step 4: Tap on Install and then Tap on confirm to complete the installation
Step 5: Now, give your iOS device a reboot and sync your iOS device with iTunes.
Note: If that does not work, Launch AppStore app and re download iBooks on your iOS Device.
Thx [MacHackPc] for the Repo ;)