If iTunes hangs after the latest firmware update for the iPhone

Since the firmware update of the iPhone, certain people encountered problems with iTunes; it hangs during synchronization. Apple proposes a means of fixing the problem rather easily:
- Launch iTunes (iPhone or iPod touch not connected)
- In the menu Store, click on " Withdraw access authorization to this computer… " and return the password requested.
- In the same menu, authorize this computer again and enter your identifier and password for the iTunes Store.
For the vast majority of the cases, the problem will be solved. Some were obliged to validate " buy" of a new free software to really complete this fix.