Veteran readers know that I enjoy a rowdy farce as much as the next guy. I laughed at all the right places in "There's Something About Mary" and even chuckled a few times at the old coot in "Next Friday." But the gags in "Big Momma's House" have been done so many times before in other films, and with so much more style, that I found it difficult to believe grown ups could find them funny. Yet there they were, surrounding me, hooting and howling like eight-year-olds at a fart festival.

Martin Lawrence plays ace FBI agent Malcolm Turner, hot on the trail of Lester (Terrence Howard, so wonderful as the acerbic friend in "The Best Man"), a murderous bank robber who has escaped from prison. Convinced that Lester will seek out his former girlfriend, Sherry (Nia Long), Malcolm and partner John (Paul Giamatti, wasted here) head for Georgia to stake out the home of her grandmother, Big Momma (Ella Mitchell), expecting Sherry and her son to take refuge there. When Big Momma leaves town for a few days, Malcolm, who is also a master of disguise, dons a fat suit, makeup and wig to masquerade as the foul-tempered old woman.

The plot is merely an excuse for a series of the sort of wheezy sketches that routinely play out on those little link-sausage sitcoms that UPN and the WB plug in between teen angst dramas and wrestling. Malcolm hides in the shower and makes faces when Big Momma suffers explosive diarrhea. Malcolm catches a glimpse of the obese woman's nude fanny and makes more faces. Oh, the hilarity of it all.

The hijinks get more strained when Malcolm assumes her identity. Martin Lawrence adopts a molasses accent and a welcoming persona to draw Sherry and her young son Trent (Jascha Washington) closer. In demeanor and appearance, he barely resembles the real Big Momma, but her friends and neighbors don't seem to notice. Most of the jokes are built around the stale notion that it's automatically funny when someone old and fat does anything athletic. Big Momma kicks butt in karate class – what a scream! Big Momma plays basketball and hangs off the rim after a slam-dunk – stop it, you're killing me!

Two jokes were particularly annoying, because even a slapstick farce should have internal logic. In one scene, the bogus Big Momma tries to show "her" cooking prowess by making fried chicken. Malcolm, unskilled in the kitchen, melts a stick of butter in a pan, then adds a big glob of Crisco and some liquid shortening to boot. With about three inches of the stuff bubbling away, he tosses the chicken into the skillet, then prances around after being splattered by hot grease. If Malcolm is such a bright FBI agent, how did he fail to ever learn that heat = danger?

Later, Sherry gets scared and asks to sleep with Big Momma. When the two curl up in the spoon position, Sherry glances backwards and asks what's pressing against her rear. Malcolm coos, "Oh honey, that's my flashlight" and the audience squealed in glee at the ribald erection joke. Pardon me, but given Malcolm's elaborate disguise, the only thing pressing against Shelly's rear would have been about 15 inches of foam padding.

If it sounds like I'm being extremely fussy, well, that's what I do when I'm extremely bored. The Kids in the Hall proved that guys in drag could still be funny. "Mrs. Doubtfire" and "The Nutty Professor" proved that comic actors playing overweight matrons could still be funny. But the only thing "Big Momma's House" proves is that even Martin Lawrence, whose exuberance made last year's "Blue Streak" fun, can't salvage witless, formulaic material like this.