Not Yet Rated?

So I'm trying to follow the rules and only show the little third graders that I have until the end of the year G rated movies. This means that I can't show films like Hook, Harry Potter, or even Flushed Away (sorry Rob). So after discussing my problem with Chris, we went online to look for a list of classic movies that are rated G. Here's some of the more interesting finds (in no particular order):

1. Modern Times
2. The Court Jester
3. 2001: A Space Odyssey
4. Gone With the Wind
5. Ben-Hur
6. The Day the Earth Stood Still
7. Giant
   
8. Forbidden Planet
9. The Ten Commandments
10. The Great Dictator
11. Planet of the Apes

I find of particular interest numbers 3, 8, 9, 11, and especially 5. Four of those movies are on AFI's Top 100 Thrills list. And yet I can't show The Adventures of Robin Hood? Or Hook, Guys and Dolls, Over the Hedge, or Shrek.

I'm tempted to show Ben-Hur just because I can.