Though it’s long spun a magical web on the printed page, E.B. White’s cherished children’s book comes across as flat, heavy and derivative in Gary Winick’s screen adaptation. “Charlotte’s Web” has none of the gossamer quality needed to bring the 1952 classic to life on screen.

It’s not the fault of the filmmakers, of course, that the little hero of the story–a runt piglet called Wilbur (voiced with generic enthusiasm by Dominic Scott Kay), saved from becoming an immediate pork chop by plucky farmgirl Fern (Dakota Fanning) and then rescued from a later trip to the smokehouse by the intervention of supportive barnyard spider Charlotte (voiced by Julia Roberts), who uses her webbing to send amazed humans messages about her little pal–now comes across as just a younger (and less engaging) cousin of Babe. But the fact that their adaptation falls so far short of Chris Noonan’s enchanting 1995 film must be chalked up to them. In the hands of Winick and his collaborators, “Web” doesn’t even manage the amusement or uplift quotient of the last “Babe” imitator, the zebra-themed “Racing Stripes.”

The problem doesn’t lie in the special effects, which are good enough, even if they never carry the sort of charge that they did a decade ago. Nor is Fanning to be blamed; she’s her usual crowd-pleasing self, happily not required to scream at the decibel level she demonstrated in “The War of the Worlds,” and though the role doesn’t necessitate much more than the concern and friendship for animals she already showed in “Dreamer,” it’s hard to imagine a tyke who could have done much more with the part. The voice talent behind the barnyard community is pretty spectacular, too, with John Cleese as a sheep, Oprah Winfrey and Cedric the Entertainer as geese, Kathy Bates and Reba McEntire as cows, and Robert Redford as a horse–but the sad fact is that the script doesn’t give them particularly funny moments to savor, and so the star wattage doesn’t shine as brightly as one might expect. And Roberts makes Charlotte a tediously soothing presence; the spider’s supposed to be a calming, maternal influence, of course, but here her delivery might be one long lullaby. In fact, the only critters that really spice up the proceedings are the cynical but helpfully hungry Templeton the Rat, whose lines Steve Buscemi really sinks his formidable teeth into, and dull-witted crows Brooks and Elwyn (Thomas Hayden Church and Andre Benjamin), whose running gags in the cornfields prove such a welcome relief from the generally tepid goings-on back at the farm that one looks forward to their interruptions.

The remainder of the human cast doesn’t make much of an impression, either. As Fern’s dad and mom, Kevin Anderson and Essie Davis are pretty anonymous, which can also be said of Gary Basaraba and Siobhan Fallon Hogan as the uncle and aunt with whom she deposits Wilbur. And though Nate Mooney offers a dose of “Beverly Hillbillies”-style hick humor as farmhand Lurvy, Sam Shepard’s narration is soporific (certainly no match for Roscoe Lee Brown’s contribution to “Babe”), and as the kindly local doctor, Beau Bridges delivers his pronouncements in so italicized a fashion that he appears to think he’s addressing mental defectives.

The real culprit in this catalogue of mediocrity is Winick, who seems to have packaged everything on the assumption that the pedigree of the property alone would be enough to make his film a success, and he needn’t give himself–or the material–any special push. The result is that, though “Charlotte’s Web” looks and sounds nice enough, it radiates familiarity and blandness. (Even Danny Elfman’s score is far from his best.) The title alone will probably draw family audiences, but as with the recent adaptation of “Curious George,” they’re likely to leave with the feeling that their published pals haven’t been done justice.

For the record, there was a 1973 animated version of White’s book, produced by the Hanna-Barbera studio responsible for so much mediocre TV fare at the time. That adaptation disappointed fans, and so will this one. As for those who come to “Charlotte’s Web” without knowing the source, it will probably seem just a pale reflection of “Babe.” Which, in fact, is what it is.