The Disney marketing folks behind "Confessions of a Shopaholic" have been working hard to suggest that they have another "Pretty Woman" in the bag.

Let the buyer beware.

Despite its top-quality cast, a bankable director (P.J. Hogan) and enticing source material (the Sophie Kinsella best-sellers), the end product is surprisingly charmless -- a shrill "Devil Wears Prada"/"Bridget Jones"/"Sex and the City" knockoff that keeps threatening to fall apart at the seams.

All those frayed ends hold together just enough to provide sufficient distraction for its targeted young female audience, but one wonders how all that conspicuous consumption is going to go over in these economically scaled-back times.

After proving her considerable comic range in "Wedding Crashers" and "Definitely, Maybe," Isla Fisher moves front and center as Rebecca Bloomwood, a spirited (and no longer British) New Yorker with a credit card for every occasion.

As fate would have it, while she harbors fantasies of working for her favorite fashion magazine, Alette, Rebecca ends up getting a gig at the parent company's financial magazine, where she becomes an instant sensation writing a column under the moniker, the Girl in the Green Scarf.

Oh yeah, she also catches the fancy of its boyish British editor and socialite's son, Luke Brandon (Hugh Dancy), while also doggedly being pursued by a grim reaper of a credit card debt collector (Robert Stanton).

While all the customary rom-com elements are in place -- including an extensive supporting cast of such consummate pros as John Goodman and Joan Cusack (as eccentric Fisher's parents), John Lithgow, Julie Hagerty, Christine Ebersole and Kristin Scott Thomas in a welcome comedic turn as Alette's oh-so-French editor -- "Shopaholic" quickly maxes out its welcome.

That bright, energetic flourish Hogan brought to films including "Muriel's Wedding" and "My Best Friend's Wedding" is in scant evidence here, replaced by a frantic forcefulness.

Meanwhile, in stitching together content from the first two Kinsella novels, the various styles brought to the table by credited scriptwriters Tracey Jackson ("The Guru"), Tim Firth ("Calendar Girls") and Kayla Alpert ("Ally McBeal") never quite coalesce into any kind of consistent tone.

More problematic is Fisher's character, which piles on the ditz at the expense of audience identification.

Behind the scenes, costume designer Patricia Field's Oscar nomination for "The Devil Wears Prada" makes her an ideal fit for the fanciful frocks on display here, but, like the rest of the picture, the mix-and-match approach doesn't necessarily add up to a winning original.