I am confused about the difference between an iPhone synch and a back-up. When I attempt a synch, it can take over 3 hours. Is it supposed to take that long? When I do a back-up, it usually takes under 15 minutes. Why such a difference? Also, when I add new photos onto my phone, should I just do a back-up tp keep the photos on my PC? How often do you recommend a synch and/or back-up? Thanks.