For a while, everything was more or less perfect with iBooks syncing with iTunes. But this week, I updated iTunes to 184.108.40.206, and all of a sudden, iBooks shows up with a "Helper application" error and now, anything that I added to iBooks since then won't sync with iTunes, which means, my iPad and iPhone can't get those new books I'm adding. I tried deleting iBooks cache already as I have seen in other places, and no change. There's also no iCloud, so that's not an issue as I've seen with others. I would like to see a solution to my problem, since I really want to add more books into iBooks on my devices, and right now, I'm looking for a solution and I hope I don't have to revert back to the previous version.