Corrected entry: At some point in the movie, it is revealed that Boss Johns, played by Matt Nable is the father of "Pitch Black" character William J. Johns, played by Cole Hauser. Hauser was 24 back when Pitch Black came out, while Nable was 41 when Riddick was released. Since the action of Pitch Black takes place 10 years before this movie, the character of Boss Johns would have been in his early 30's at the time. Did he really have a kid when he was 7?
Corrected entry: Shortly after Santana tries to rape Dahl on the station floor, we see a vast amount of blood all over the floor where they had been lying; however, when it's revealed that they are both Ok and Dahl had simply beat him up, only his mouth is bleeding. The amount of blood on the floor was way too much to have come from a split lip.
Correction: You are referring to the real life ages of the actors not the in-movie ages of the characters which was never disclosed. Boss Johns may very well be 41 or 51 for all we know. Artistically speaking, the actors may represent any age they are meant to be in the movie, it would only be a mistake if they look radically older or younger than they're meant to be.
Let's not forget cryo sleep.