Sunny comedy with little shine

Trouble in paradise. That's the overly familiar premise of this sun-poisoned comedy.

Four couples from a snow-crusted suburb set off for a tropical retreat. Three of them are expecting rum, rumba, and relaxation. So they're more than a little peeved when they find out they're enrolled in an intensive relationship workshop.

Couples Retreat introduces its cardboard characters and sets up the plot efficiently and with a fair degree of wit. But once this skit hits the sand, all towels are off. The story and the humor get progressively skimpier than an Ipanema bikini.

The alpha males are played by Vince Vaughn and Jon Favreau, which may surprise many of us who thought they were the same person. Jason Bateman and Faizon Love are the more pathetic guys, roles that stifle the considerable comic talents of both.

Their female companions are played by (respectively) Malin Akerman, Kristin Davis, Kristen Bell, and Kali Hawk.

There is surprisingly little exploration of gender differences in the script written by Favreau, Vaughn, and Dana Fox. Instead, Couples Retreat takes aim at holistic pretension, an easy and tired target.

The resort's guru (Jean Reno with a ratty ponytail) is "the world's foremost couples whisperer."

The other played-out vein of humor is that the island's staff, studs with indecipherable accents, use an approach that is markedly feely-touchy. That recurring gag culminates in an obvious and offensive yoga session full of sexual pantomimes. It makes Borat look subtle.

There is a sparkly turn for the reliably funny John Michael Higgins as a skeptical marriage therapist.

The movie, a tropical version of 1978's California Suite, is typical of modern comedies: a flip premise that gives way to a plot held together with more raised stitches than a baseball.

In the end, after all the mystic counseling and couples' skill-building exercises, it turns out that all they needed to heal their relationships was hot sex.

They could have gotten that at Club Med - without having to explore their feelings.