I think I must be missing something but I can't get anything other than a 404 for credit ids.

As an example I'm trying to find Matt Damon in The Bourne Identity. Using http://api.themoviedb.org/3/movie/2501/credits?api_key=API_KEY gives me a credit_id of 52fe435ac3a36847f804dffd.

Trying to get that id using http://api.themoviedb.org/3/credit/52fe435ac3a36847f804dffd?api_key=API_KEY gives me a 404.

How am I supposed to find credit info? Thanks