A pretty high-school science geek with a penchant for figure skating uses physics to land a better lutz in "Ice Princess," a follow-your-dream movie that is far less cliché-riddled than you might expect from such G-rated Disney fare.

Michelle Trachtenberg (the little sister from "Buffy the Vampire Slayer") stars as Harvard-bound misfit Casey Carlyle, who combines her two passions hoping to win a scholarship by proving science can improve her skating. In the process, she discovers her calling may lie on the ice instead of in a lab -- although there are many obstacles to overcome, including a disapproving dowdy-feminist mom ("I just can't get past the twinkie little outfits," frowns the wonderfully wry Joan Cusack) and some backstabbing ugliness from fellow competitors.

But the delight of "Ice Princess" is that there's more to almost every character than meets the eye. Kim Cattrall ("Sex and the City"), for example, plays a disgraced former champion skater who begrudgingly helps Casey while vicariously coaching her beautiful in-crowd daughter Gen (talented Hayden Panettiere) toward a career on the ice. Appearing to be antagonistic stereotypes at first, both reveal unexpected aspects of empathy and authentic human frailty as Casey's rapidly growing talent threatens Gen's standings in local competitions.

The third act is more predictable as Casey and Gen advance to regional championships, where real-life skaters (and obvious non-actors) Michelle Kwan and Brian Boitano stumble through roles as ESPN play-by-play commentators, offering up lifeless voice-over exposition that tells the audience what to think of Casey's performance. Contrived complications arise in the last 15 minutes to keep the plot afloat -- as do a few false dilemmas. Why must Casey choose between college and skating? Couldn't she just defer Harvard for a year while she tests her talent in competition?

But for the most part director Tim Fywell ("I Capture the Castle") keeps the stock elements in check, including a romance with a cute Zamboni driver (Trevor Blumas). More importantly, he doesn't rely on the physics gimmick or on his skating doubles (who are seamlessly edited into scenes of his actors on the ice) to create a spectacular sports-underdog climax.

He lets the performances drive the story and helps Trachtenberg create in Casey such a credible, likable, easily discombobulated Everygirl that even when "Ice Princess" slips on one of its more conventional plot points, it doesn't effect the picture's overall performance. Like Casey herself, "Ice Princess" gets up, dusts off and glides gracefully into its next, more intricate, character-driven maneuver.