After the released of iOS 5.0.1 Untethered Jailbreak many users reported an error i.e. iBook crashing issue after the iOS 5.0.1 Untethered Jailbreak.Everytime you launch the iBook App it will crash.There are two methods to solve this issue.
First Method To Fix iBook Crashing Issue:
STEP 1:Open up Cydia and go to Manage>Sources>Edit and add a new repo “repo.insanelyi.com”
STEP 2:After adding search for “iBooksFix2” download this pakage and install it.
Second Method To Fix iBook Crashing Issue:
STEP 1: Download this file from here.
STEP 2: By using SSH or iPhone explorer add this file to “/var/root/Media/Cydia/AutoInstall”.
If the above mentioned folder exist then fine if not you can create by yourself.After adding file reboot you iPhone,iPad or iPod touch and congrats you have fixed the iBook issue.