I have had to exchange my iPhone5S for a new one at the Apple Store last Saturday, because the glass was bent for some reason and would pop out of its frame on one side. (known issue as described in the apple forums here). Fortunately they have swapped it right away as exchanging the glass would not be allowed because of touchID.
So no problem, back home restore the phone from iTiunes backup.
It worked but I noticed today that Push notifications stopped working.
Apple Support office was already closed, so I browsed the Apple Support Forums for all the odds of solution suggestions. However all of them didn’t help except one, which is – according to the feedback – the solution that works in the majority of all cases).
Uninstall and reinstall the “find my iphone” app!
Have fun with your iPhone and iOS7!