After jailbreaking iPhone 4S/ iPad 2 iOS 5.0.1 with GreenPois0n Absinthe some users are facing issues with launching iBooks and some are able to view images and content on DRMd documents. iOS developer, @xvolks has found the issue and updated Corona 1.0-6 untether tool is on its way.
Xvolks has traced the issue being in the PNG format and confirmed that @planetbeing pushed a patch on corona git repository that makes another patch on the kernel for fixing issues on iBooks.
Additionally, Pod2g has just confirmed that @planetbeing has now fixed the Corona issues with iBooks DRMd books and will soon be releasing the Corona 1.0-6 version.
Xvolks has also fixed the iBooks launch issue and helped the team to update Corona 1.0-5 to include iBooks fix. Using facing the issues can just run the updated Corona version, once released to fix the iBooks issues with their jailbroken iPhone 4S or iPad 2.