After taking a few weeks away from this game, I decided to give it one last go. I created a new gamer profile on my Xbox and played the game from the very beginning of Episode One to the end of Episode Two. I sat thru the camcorder video at the end. Hid my eyes during the teaser trailer for Episode Three. After waiting what seemed a lifetime, BAM! I got the stats screen loaded up!
This would be my suggestion. Try making a new profile on your system and try it again.
Hope this helps! Good luck!