Before you can sync an iPad, iPhone, or iPod touch running iOS 4.3, you’ll need to update to iTunes 10.2.x on your Mac. After you do, be on the lookout for a few bugs that rode in on the back of the new iTunes.
The most common symptom, as reported by numerous users (and you can include me in this group), occurs when an iOS device’s synchronization reaches its final step (Step 5 if the device was backed up in Step 1). Even though you are almost at the finish line, a message appears that says you are “Preparing to sync.” In a sense, the message is accurate. In terms of the time remaining until the sync is complete, you really are just getting started. Step 5 will likely take longer than the time of the previous four steps combined. It may take so long that you decide to cancel the sync and try again. If so, it will be to no avail. The delay will happen again.
What should you do? There appears to be no single guaranteed fix. However, at least one of the following should do the trick:
- Let the sync go to completion, no matter how long it seems to be taking. After it is done, the odd behavior in the last step may no longer recur (at least not for that iOS device).
- Update from iTunes 10.2 to 10.2.1. Many (although not all) users report that the latest update update fixes the bug.
- Download the iTunes installer from Apple’s site, rather than using Software Update. Several users found that, after updating again using the Installer, the symptom vanished.
- Delete the iPod Photo Cache folder. To locate this folder, select the Show Package Contents contextual menu command for the iPhoto Library file (typically found in the Picture folder of your Home directory). The iPod Photo Cache folder should be in the list of items that appears in the package window. Drag the folder to the Trash. (If you sync with Aperture rather than iPhoto you'll look for this folder inside the Aperture Library package.)
As the last fix implies, the bug has something to do with syncing/importing photos. This makes sense, as Step 5 where new photos are imported to your iOS device.
Other users have reported a variation of the bug: Photos on your iOS device are cited as deleted, re-optimized and re-synced with each sync. The more photos you have stored on your iOS device, the longer this process takes. The suggested fixes here are the same as the ones I already listed.
If you can’t get anything else to work, there’s one final work-around: Turn off syncing of photos for your iOS device. When asked, select to not remove the photos currently on the device. As long as you don’t need to add any new photos, you can leave things this way. You’ll need to temporarily reverse the change, which will revive the delay, when you want to sync new photos.