`The Lizzie McGuire Movie'.(Knight Ridder Newspapers)

Byline: Christine Dolen

Lizzie McGuire isn't a real person, but she's hugely popular. The pretty-if-klutzy middle schooler is the star of her own daily Disney Channel television series, voted favorite TV show at the latest Nickelodeon Kids' Choice Awards. Hilary Duff, the actress who plays Lizzie, made her singing debut with the single "I Can't Wait" and has already starred in "Cadet Kelly" on the Disney Channel and opposite Frankie Muniz in "Agent Cody Banks."

So the success of "The Lizzie McGuire Movie," in which Duff acts AND sings while playing both her beloved character and an Italian look-alike, is probably a slam dunk. That doesn't mean it's a great movie. It isn't, though that probably won't matter much to Lizzie's legions of fans.

Adhering to the comic-fantastic tone of the TV show, the movie sends Lizzie _ whose penchant for physical foul-ups has ruined her junior high graduation _ off to Rome for an educational tour. Her best male friend, Gordo (Adam Lamberg), their slow-but-sweet pal Ethan (Clayton Snyder) and Lizzie's snooty tormentor, Kate (Ashlie Brillault), are also off to The Eternal City hoping for adventure.

Faster than you can say "hottie" in Italian, Lizzie hooks up with dishy Paolo (Yani Gellman), a pop star whose act _ and romance _ with a dark-haired Lizzie double named Isabella are both FINITO. Smooth-as-gelato Paolo persuades Lizzie to impersonate Isabella at a major music awards show. With the help of a conflicted Gordo, Ethan and, amazingly, Kate, Lizzie manages to break away from the drill-sergeant tour leader, Miss Ungermeyer (Alex Borstein), for costume fittings, beauty treatments and some romantic excursions around Rome with Paolo.