I'm posting this in case some one else runs into this.
I backed up my iPhone 4S and then updated to iOS6. It went smoothly until I started using the iPhone and the screen would suddenly go very dark. And every time I tried to move Passbook off of my Home screen, I would move it and when I pressed the Home button, the screen would go dark and the Apple logo bootup screen would pop up for about 5 seconds. The only way to restore the screen brightness would be to go to settings. The brightness slider would be where it normally is and as soon as I tap it the brightness would restore to normal. I went in and restored from the latest back up and that SEEMS to have corrected the problem. I was able to successfully move Passbook off to another screen.
I backed up my iPhone 4S and then updated to iOS6. It went smoothly until I started using the iPhone and the screen would suddenly go very dark. And every time I tried to move Passbook off of my Home screen, I would move it and when I pressed the Home button, the screen would go dark and the Apple logo bootup screen would pop up for about 5 seconds. The only way to restore the screen brightness would be to go to settings. The brightness slider would be where it normally is and as soon as I tap it the brightness would restore to normal. I went in and restored from the latest back up and that SEEMS to have corrected the problem. I was able to successfully move Passbook off to another screen.