With his best cast ever, topped by Oscar winner Kathy Bates and the great Alfre Woodard, and his most cinematically polished production to date, "Tyler Perry's The Family That Preys" shows grand advances in the filmmaking education of playwright-turned-filmmaker Tyler Perry. It's also his soapiest film yet, an overwrought melodrama of sibling rivalry, infidelity, family business power plays and terminal illness.

And "Family That Preys," which opened last week, is yet another example of how the mini-mogul from Atlanta is his own worst enemy, raiding his cupboard of his popular but pandering stage plays and not bothering to script-doctor them for the screen. As sophisticated as the filmmaking becomes, Perry's scripts are still painfully unsophisticated grab-bags of melodramatic cliches, tired jokes and sermonizing.

Woodard and Bates are Atlanta matriarchs, single mothers and longtime friends. Alice (Woodard) runs a diner where she's raised the money to send spoiled daughter Andrea (Sanaa Lathan) to college, which other daughter Pam (Taraji P. Henson) resents. Charlotte (Kathy Bates) is a construction mogul content to keep her spoiled son (Cole Hauser) under her thumb at the family business.

How close are the families? We meet them on Andrea's wedding day, which takes place at Charlotte's expense and in Charlotte's vast antebellum mansion. This really IS the New South.

Andrea doesn't appreciate all this.

"If she wants to be Mammy," she sneers about her mom, "I can be Stepin Fetchit," if only for one day.

Cut to four years later, and Andrea and her husband, Chris (Rockmund Dunbar), are both working in Charlotte Cartwright's construction firm, with Andrea now successful and resentful of a man she's grown ashamed of. There are troubles in the younger Cartwright's marriage, too. And the business has been invaded by a corporate infighter, too broadly played by Robin Givens. Perry plays Pam's husband, Ben, Chris' brother — the guy Chris wants to team with to form their own construction company, something we can tell is a very naive idea.

And with all these stresses, all Charlotte wants to do is persuade Alice to be Louise to her Thelma for a road trip in a classic Cadillac convertible she's bought.

It's a film of soap-opera close-ups capturing the fabulous grooming and makeup of the gorgeous cast, of immaculate sets that don't look lived in, of B-unit road trip shots of the Seven Mile Bridge, the Grand Canyon and the French Quarter. There's a lot of church in here, a choir number, a baptism "out West" plainly filmed in the Georgia mud.

But everything that crosses the screen feels warmed over. Perry's success hinged on his tying together broad stock characters and generic situations with an Oprah-inspiring message slapped on top.

Perry has created a franchise out of his name and his formula for reaching his audience. But the steady improvements in his filmmaking skills are married to steady declines in the box-office take of his movies. He's hit his own glass ceiling.