Weird. I works for me. And when I look at the web pages, both the old and redesigned sites have "Rated PG-13 for some sexual content" on the main page.
I have it too. Example: http://www.imdb.com/title/tt0425326/ used to say "Rated PG-13 for some sexual content" but after clearing that field and reimporting now just says "PG-13".
After last update there is no more reason why is something rated R, PG-13 etc. Its just say "R", and before it was "Rated R for violence and language."