"Zack and Miri Make a Porno" isn't pornographic. It's just dirty in a juvenile kind of way.

Kevin Smith, director of the sublime "Clerks" flicks and the amusing New Jersey cycle of "Mallrats," "Chasing Amy," "Dogma" and "Jay and Silent Bob Strike Back," teamed up with Seth Rogen and lost his way.

Rogen is the unlikely movie star from "Knocked Up" and "Pineapple Express," and assorted sordid Judd Apatow pictures, who does his usual loser/slacker/horny business in "Zack and Miri Make a Porno." It wears badly.

Smith and Rogen are unique characters in the glitzy gallery of Hollywood. To their credit, movies like Smith's "Jersey Girl" and Rogen's "Superbad" are sweet and engaging in a nerd boy's kind of way.

"Zack and Miri Make a Porno," however, is simply the cinematic equivalent of immature guys hiding sex magazines under their bed, who maybe missed a shower or two, yearning for girlfriends. You don't really want to hang with them unless you're like them.

"Zack and Miri Make a Porno" centers on platonic roommates Rogen and Elizabeth Banks (impressive in a different genre as Laura Bush in "W.") who run out of money; the gas and electric are turned off during a snowy, midwinter Pittsburgh.

At their 10-year high school reunion, they run into a gay porn star named Brandon St. Randy (the randy Justin Long), who's the lover of former football hero Brandon Routh (far from his "Superman Returns" role).

Long, who's Mac in those Mac vs. PC commercials, is hilarious, describing his love life and the money he earns in graphic detail (the movie appealed its initial NC-17 rating and got an R). Zack and Miri are inspired to make a sex film of their own.

The language, as expected, is base, focusing on orifices and bodily fluids. For the first time in both Smith's and Rogen's work, the attitude doesn't rise from the puerile. "Zach and Miri Make a Porno" wallows in cheap gags. Not that there's anything wrong with that, if they're funny.

In the cast are actual porn stars Traci Lords (she of the notorious teenage past) and Katie Morgan of those late-night, sexually explicit HBO specials.

It's a difficult trick for porn stars to make the transition to straight movies. It doesn't happen. And in the — oh, lord! — performances of Lords and Morgan, it's easy to understand.

Jason Mewes, a Smith regular (he's Jay of the "Clerks" movies and "Jay and Silent Bob Strike Back"), gets the most graphic sex scenes; the guy is a comedic natural, brightening the otherwise dim shenanigans.

"Zack and Miri Make a Porno." Rated: R. Running time: 1 hour, 41 minutes. 2 stars.

To find out more about Lee Grant and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.

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