I have the Facebook app on my iPhone and I have "Contacts sync" turned on within the facebook app. It works great until I plug the phone into iTunes. I get a message saying "this sync will change more than 25% of the entries in your contacts, do you wish to proceed?". I always say no but then it turns the facebook sync off on my phone and removes all the facebook info. I just realized I probably should say "yes" to the popup I mentioned previously, does that makes sense?