Watching the low-voltage comedy Guess Who is like drinking a Coke from a fountain that’s not dispensing enough syrup. There’s some flavor, but it tastes more like cola-scented water than actual Coke. The movie isn’t bad, but it is weak, and the flavor comes from two comedies about awkward introductions to prospective in-laws – Katharine Hepburn and Spencer Tracy’s Guess Who’s Coming to Dinner and Ben Stiller’s Meet the Parents. Ashton Kutcher, who doesn’t profit from comparisons to Sidney Poitier or Ben Stiller, plays a guy whose fiancee hasn’t warned her (African-American) parents that her (white) boyfriend is “pigment-challenged.”

Coming to Dinner was almost 40 years ago, but Guess Who, which is set in the present, updates it only about 20 of those years. There’s a raw, satiric idea in here that hints that racial politics haven’t changed nearly as much in 40 years as they should have.

Occasionally, Guess Who semi-kinda-almost addresses those issues – there’s a funny, uncomfortable scene when Kutcher actually does come to dinner and is intimidated by his future father-in-law (Bernie Mac, as always a sly presence) into telling racial jokes. This scene gets at discomfort about race in a unique way, but Guess Who shoves that stuff beneath the surface almost immediately afterward and never gets back to it.

In its place we get jokes that are about as fresh as gossip about Tracy and Hepburn: two heterosexual guys awkwardly spooning when they’re forced to share a bed, an is-he-or-isn’t-he-gay party planner, dopey dancing ... you get the picture. There’s also a Big Secret that remains secret for the whole movie for no reason other than plot convenience.

I would not be surprised to learn that there exists an earlier Guess Who script that is more pointed and relevant. Guess who wishes he could see that one instead of this one?

Grade: C © 2005, St. Paul Pioneer Press (St. Paul, Minn.).