Repeat Alerts not working on the iphone 5 Why doesn't the repeat alerts work on the iphone 5 for text messages? After the initial alert. It doesn't make any sounds to notify that you have an unread text despite me setting it to remind me up to 10 times in the notification center.
Just got my iPhone 5 2 days ago and noticed this as well.  Was on iOS 6.0.1 have since upgraded to 6.0.2 and same issue.

I've noticed if I leave a particular persons text messages up, I do not get another notification.  However, if I press the home screen and go back to the main screen I'll then receive audible notifications.

I did restore from my iPhone 4S backup via iTunes.  Later today I'm going to wipe the phone and rebuild from scratch and see if that helps.