Edit: After half day, my wife’s Mac started having the same problem. I have then applied the solution that I found in the Apple
iTunes 10.4 Released To The Public
Apple have released today there latest edition to the iTunes family , iTunes 10.4
Apple said “iTunes in the Cloud beta lets you automatically download new music, app, and book purchases to all your devices.
Or you can download only the stuff you want to just the devices you want.* It’s all part of iTunes 10.4.”
Download iTunes 10.4 From Here
We have FULL Coverage of the iPhone 5 Live Event and other Apple events Here and on Youtube