It doesn't take a rocket scientist to figure out that the target audience for "What a Girl Wants," directed by Dennie Gordon (2001's "Joe Dirt"), is pre-teen and teenage girls. Any truly good movie, however, is able to transcend sex and age barriers so that it can be enjoyed by just about anyone with an open mind. "What a Girl Wants," which plays like this year's version of 2001's "The Princess Diaries," achieves this some of the time, but not always. It is a funny and sweet little ditty, well-meaning and with its heart in the right place, but it ultimately overstays its welcome. At 102 minutes, it feel like it is well over two hours, and includes not one, but two, annoying "trying-on-clothes" montages.

Daphne Reynolds (Amanda Bynes) has lived contentedly with her single mother, Libby (Kelly Preston), for all of her 17 years, but hasn't been able to shake the missing hole in her life where her father is supposed to be. The story goes that Libby fell in love with Henry Dashwood (Colin Firth) while vacationing in Morocco. They were married, but when Henry returned to his royal home in England, his stuck-up friends and advisors sent Libby packing. Out of their brief relationship, Libby gave birth to Daphne. With summer break coming up, Daphne buys a plane ticket and books it to England, determined to make up for lost time with Henry, who doesn't even know he has a daughter.

Henry, who is running for a seat in the House of Commons, welcomes Daphne into his mansion, much to the haughty chagrin of his power-hungry fiancee, Glynnis (Anna Chancellor), and soon-to-be stepdaughter, Clarissa (Christina Cole). In her effortless, free-spirited way, Daphne shakes up all of their lives and her father's candidacy to Parliament. But as Henry and Daphne start to form a connection, he urges her to start acting more like a debutante—something she clearly is not meant to be—putting a strain on Daphne's blossoming romance with teenage musician Ian (Oliver James).

Based on the 1958 play, "The Reluctant Debutante," by William Douglas Home, "What a Girl Wants" is first and foremost a starring vehicle for rising teen star Amanda Bynes (who rose to fame on Nickelodeon's "The Amanda Show" and in 2002's "Big Fat Liar"). As Daphne, Bynes is a natural comic talent, but much of her acting is just a little too mannered and unpolished for its own good. As cute and eager-to-please as she is, Bynes' million-dollar smile and ever-widening eyes tend to grow annoying after a while.

As estranged father Henry Dashwood, Colin Firth (2001's "Bridget Jones's Diary") adds a touch of class to the proceedings, as do Eileen Atkins (2002's "The Hours"), as Henry's sympathetic mother, and Kelly Preston (2003's "View From the Top"), as Daphne's singer mom, Libby. Preston, too often wasted in parts below her abilities, is quite good here. Newcomer Oliver James adds charismatic young hunk appeal as Daphne's new boyfriend, Ian.

Where "What a Girl Wants" falters is in its overriding predictability and blandness. With all of the plot developments long foreseen before they arrive and the latest hip pop song playing in practically every scene, the film wears you out. As fluffy and innocuous as the first two acts are, the overlong and schmaltzy last thirty minutes become an endurance test. At this point, any thinking viewer will know where everything is headed, and so when the movie continues to hem and haw around, throwing on one tearful confrontation and false ending after another, all it manages to do is frustrate. The tacked-on epilogue, especially, should have been excised.

In the end, "What a Girl Wants" sends out a strong message about the importance of sticking to your beliefs and being yourself. It's too bad director Dennie Gordon and screenwriters Jenny Bicks and Elizabeth Chandler couldn't have cut to the chase, giving audiences the benefit of the doubt and making their point in a more time-efficient manner.