I upgraded both to iOS 8.1 and OS X Yosemite yesterday and lost 150 contacts that remain on my iPhone but will not sync to the Mac. Turning the contacts feature off and on seems to delete contacts (as I have had to re-enter) contacts and only 341/500 have synced to my Mac. Most of these contacts showed up fine in Mavericks and IOS 7.1. Does anyone have anything I can try? Thanks..