I'm trying to fix some errant iPhone 4S syncing issues with iTunes, nothing serious, just annoying, and at the end of sync there's a large .mp3 file that always takes time syncing, even though it hasn't been added/modified and many others like it are treated correctly (i.e., not synced since they're already on my iPhone). I see no problems with the file itself in my iTunes library. I'd like to have it on my phone so I don't want to delete it or uncheck it in my iTunes library. Ideas to help diagnose? I recently ran a Restore in iTunes, which fixed a few odd iPhone behaviors but not this one.