Three irreversible curses torment A Cinderella Story. The first is that Hilary Duff's new picture trails the recent release of ''Mean Girls'' starring Duff's quote-unquote archrival, Lindsay Lohan. And in that quote-unquote competition, Duff has been handed far tinnier weapons with which to defend her title of teen queen. The one-time love interest of Frankie Muniz's Agent Cody Banks plays Sam Montgomery, a West Coast high school senior whose college plans are thwarted by a stepmother (Jennifer Coolidge) not so much wicked as possessed by the Botox devil. Prince Charming (WB rep player Chad Michael Murray) is Austin Ames, a mystery classmate Sam meets in an online chat room. Her fairy godmother (''Jerry Maguire'''s winning Regina King, who needs a casting godmother of her own) is a diner waitress.
The second curse is that this contemporary variation on the old tale, directed by Mark Rosman (one of Duff's TV helmers from her ''Lizzie McGuire'' days), follows the recent release of ''Ella Enchanted.'' And although ''Cinderella'' is set in the very now realm of L.A.'s San Fernando Valley, where a princess is ID'd by the cell phone she drops rather than the glass slipper she loses, the movie's laugh lines feel prematurely aged (''In true L.A. fashion, it's not about who you are, it's about what you wear!''), especially when compared with the freshness of ''Ella'''s premise and the spunky loveliness of Anne Hathaway in old-fashioned sweetheart gowns. Self-referential pop dialogue about the Olsen twins and ''The Fast and the Furious'' doesn't make up for the moviemakers' lack of anything original to say, whether about mean girls, stepparents, or the difficulties of finding a spot in the student parking lot of an affluent suburban high school.
The third and most dire curse, though, is that when not unnecessarily bland, synthetic, and indistinguishable from undistinguished teen TV, ''A Cinderella Story'' is unnecessarily coarse and dumbed down, with every character except Sam and Austin subject to perfunctory ridicule. Coolidge squanders her usually tonic blowsiness, saddled, in the first produced screenplay by Leigh Dunlap, with liposuction jokes too wrinkled even for Joan Rivers. And Duff, an appealing, well-scrubbed, 16-year-old phenom, appears imprisoned in her own magic kingdom of carefully chaperoned celebrity.