iOS 6 update on 4s - sound issues - reinstall iOS?

[StingMe]

The update to iOS6 went without a hitch on my 4 but when my sis updated her 4s she began to experience the sound issues that seem to be affecting some percentage of updates...no sound, unable to adjust ringer volume, disappearing music volume control, etc.

What is the bet way to give her a fresh start akin to reinstalling the OS? Will a backup, reset, and restore do the trick or are there more drastic measures?

Thanks!

[cbelt3]

Well, the normal sequence of fixing Weird Stuff is:

1- Close all apps
2- Restart
3- Restore
4- Go to the Apple Store and whine bitterly

[StingMe]

So if iOS6 won't behave on this 4s and Apple provides no way of going back to iOS5, what will they do if she has to resort to your step 4? Give her a new 4s that will work with iOS6? The other 4s in the household accepted the update without any issue.

As it stands now, her iPhone is virtually unusable...