Hi Jason H,
So far the only thing that has helped has been to put the iPad into flight mode when I want to use iBooks.
I have done all the things mentioned in the link you provided except reinstalling iBooks. With the update to iOS 8 I have not activated iCloud Drive, (since been advised not to do that until the next Mac OS update in three weeks). I am backed up to my iMac but I would hate to lose the 300+ books that are stored on the App.
If I can be reassured I would not lose the iBooks' 'data' if I were to reinstall iBooks I could try that.
Since the problem has ONLY occurred since the update to iOS 8 on the iPad, and it has been widely reported as a problem since the upgrade, I am not convinced the problem is the App.
Could you explain why reinstalling iBooks would correct the problem.
I am assuming the reason the iBooks now works with the iPad in flight mode is that the problem is to do with some interference that is happening with the relationship the iPad and iOS 8 is now having with the 3G Data Sim card.
Thanks