AppleMobileDeviceHelper must be forced quit to sync iDevice with iTunes

I have 2010 MBP running Mavericks OS X 10.9.4. When I try to connect my iPhone 5s running iOS 7.1.2), the iTunes freeze or hang. I let it run for about 1 hour, and it still looping with color circle. I tried to Reset Sync history using the steps listed http://support.apple.com/kb/TS2481 with no luck.

I even tried to delete the AppleMobileDevice.kext file and iTunes can run smoothly but it can't detect my iPhone while iPhoto can detect my iPhone and export picture without any problem, then I uninstall and reinstall iTunes hoping the AppleMobileDevice.kext is the source of the problem and fixed by reinstalling the iTunes. But without luck. At this moment, I have to force quit AppleMobileDeviceHelper service from Activity Monitor a couple times before it actually sync between iPhone and iTunes.

Please advice.