Sync pains

Hello there.

I'm using a macBook Air with OS X 10.10.4 Yosemite and iTunes 12.2.1.16.

Usually iTunes recognize the iPad and the iPhone 5 on the fly and the iPhone 6 only with USB cable.

In the past iTunes releases I never had this issues but the problem is that iTunes refuse to sync the iPhone 5 (both WiFi or USB connections) while, in other hand, sync without any problem the iPhone 5 and the iPad.

Yes, is the same notebook, same hw/sw configuration, same wireless network, all the iDevices run the 8.4 iOS.

The only message I get when iTunes fail to sync the iPhone 6 is that "... wasn't unable to connect to the server ... " and yes, the internet connection is perfectly working of course.

Any idea, other than punch a hole in the middle of the iPhone screen?

;-)

Cheers.