I am definitely starting to regret downloading IOS 5 b/c of all the sync issues I am dealing with. I have Iphone 4, Itunes 15.0 running on Macbook (10.5.8). My restore session after IOS 5 upgrade stuck and restarted a few times. After the upgrade, I have two major issues. 1. Ibooks does not work anymore. I tried deleting and reinstalling several times. It doesn't work. 2. Itunes does not sync with my iphone. I tried checking and unchecking sync options, rebooting both iphone and the computer etc. Nope. It says it's backing up, starting to sync and then jumps to step 6: cancelling sync. I tried dragging my ringtones and it says "The Iphone cannot finish syncing because the sync process failed to start" or something similar. While trying all these, I also deleted my apps (I know foolish!). Although I got them back from ICloud, my data is gone. At this point, I think my only option is to back up Itunes, remove Itunes completely and reinstall. Any other ideas?