I got an iMac first, let me call that iMac "A", and I used to sync my iPhone to A. Then I got a Macbook, let me call that Macbook "B". When I use B for the first time, I used Migration Assistant to transport all the files and settings from A. After that, when I use A and B in the same Wi-Fi network, both of their iTunes shows my iPhone on their list. And I can sync my iPhone to both A and B without the warning window showed up. But, I can't manage both two iTunes library at the same time, so I want to choose only B to sync my iPhone. And I found out that, in fact, when I turn on the Wi-Fi sync option, my iPhone always trying to sync with A, not B. Now I can only use cable to sync my iPhone with B, and that's not over, I found sometimes all of my apps are selected when I tried to sync my iPhone with B, no matter how many times I changed that setting, the next time all the apps will come back to be selected again! I think that's A bothering B... How can let my iPhone forget A and only accept B?