Terry Bradshaw should thank Leslie Nielsen.

Bradshaw, whose naked behind triggers instant laughs and groans in "Failure to Launch," is outdone in "Scary Movie 4" by 80-year-old Leslie Nielsen as the president of the United States who unwittingly vaporizes his clothes. Of course he doesn't realize it because he's not just dumb but dumber.

Regina Hall, right, is involved in a spoof of "Saw" in "Scary Movie 4." "Scary Movie 4" Rating: PG-13 for crude and sexual humor throughout, some comic violence and language Starring: Anna Faris, Craig Bierko, Regina Hall Director: David Zucker Post-Gazette Family Film Guide review of 'Scary Movie 4' "Scary Movie 4" Web site

The same might be said of "Scary Movie 4," the new installment of the franchise, which started in 2000 by poking fun at such movies as "Scream," "The Sixth Sense," "Blair Witch Project" and "The Matrix."

This time, director David Zucker and writers Craig Mazin and Jim Abrahams spoof "Saw," "The Grudge," "Brokeback Mountain," "War of the Worlds," "Million Dollar Baby" and "The Village," not to mention Tom Cruise in one of his more memorable pop-culture moments.

The comedy does manage to weave all of these stories together like a daffy daisy chain, but it also depends on juvenile or gross-out humor. You either have a taste and tolerance for it or you don't, and despite having seen all of the movies being skewered, I think I laughed twice (although a preview audience often roared). Maybe it's a generational or gender thing, and I fall on the wrong side of both lines.

Take, for instance, a scene in which the wide-eyed home health worker Cindy Campbell (Anna Faris) thinks she's giving a bath to a nearly catatonic old lady (Cloris Leachman), but instead of reaching into the clean water, she dips her sponge into the bed pan and drenches her in urine.

Or the blind villager (Carmen Electra) who mistakes the meeting hall for her house or, more specifically, bathroom. You get the picture and, in the movie, sounds.

In addition to Faris, Regina Hall returns as Cindy's sex-crazed friend, Brenda. The movie also stars Craig Bierko as the Cruise character from "War of the Worlds," Molly Shannon as his ex-wife and a bearded Bill Pullman as leader of the 19th-century village that counts Chris Elliott as the resident idiot. Lots of familiar faces turn up in cameos, starting with Dr. Phil McGraw, Shaquille O'Neal and good sport James Earl Jones.

In the end, "Scary Movie 4" reminded me of "Saturday Night Live," which isn't funny anymore, either.