I bought my new Iphone on Tuesday, but what I got home it wasn't syncing with my Mac. I thought for sure it was my Iphone. Yesterday I brought both my Mac and Iphone into the new Apple store in Roseville. I worked with several Mac Geniuses as it was a very odd situation. Everyone was very patient and they were committed to making this right for me. Eventually the store manager lent a hand and he was able to fix the problem. Turned out being caused by corrupt files in my library folder. It took quite a while to resolve the problem, but bottom line...they fixed it for me and I'm happy. Thanks guys!!