Twenty-nine years later, there's a new "Shaft" in town and, once again, the song (and, to a lesser degree, the star) is better than the actual movie.

According to Director John Singleton ("Boyz N the Hood," "Rosewood"), Producer Scott Rudin ("The First Wives Club," "Clueless") and star Samuel L. Jackson, "Shaft" was, to put it mildly, a troubled shoot. Each man had his own idea of how to properly present the American icon and their on-set warfare spilled over to the interview circuit. The friction shows onscreen. "Shaft" is a wildly disjointed film that makes a number of fundamental mistakes.

"Who's the black private dick who's a sex machine to all the chicks?" goes Isaac Hayes' theme song. But this time around, Shaft is a New York City policeman so busy being pissed off that he doesn't have time to think about sex. Well, at least they got the black part right. To his credit, Jackson forced a rewrite so that Shaft resigns from the force to become a private detective early on (Rudin wanted him to remain a cop because he found the notion of a private citizen running around NYC shooting people unrealistic). Despite Jackson's insistence on authenticity in that area, he misses the essence of the character.

Richard Roundtree's John Shaft is a self-assured, earthy stud, while Jackson's John Shaft (the nephew of the original) is brittle, cerebral and explosive. Put simply, Roundtree simmers while Jackson boils -- and the difference is crucial. Around 20 minutes into the film, viewers get to do their own comparison when Jackson's Shaft hooks up with his uncle at a neighborhood bar. Roundtree saunters onscreen and instantly establishes the sense of unforced cool that inspired Isaac Hayes' song. Finally, here's the real Shaft, which begs the question: Why didn't John Singleton hire Richard Roundtree to star in the new film? It can't be his age – Jackson is only six years younger than Roundtree. The veteran actor looks as good as ever, so why make him settle for a glorified cameo appearance?

Apparently, the thought never occurred to Singleton. From the beginning, he envisioned Roundtree only as a supporting player, with a younger actor in the lead role. Reportedly, the studio would not agree to finance the movie without a star of Jackson's caliber above the title. But I believe that if Singleton had pitched the story with Roundtree as the central figure and a hot actor like Jackson taking the secondary spot, someone in Hollywood would have been smart enough to pony up the money.

Understand, I appreciate the enormous talent of Samuel L. Jackson, but in the years following his "Pulp Fiction" breakthrough, I've grown a bit tired of watching displays of his righteous anger. Here, Jackson makes Shaft come off more like a loose cannon than a savvy maverick. The guy needs to spend some quality time with his uncle and learn how to smooth himself out.

The script needs smoothing out as well. The story begins with Shaft trying to nail wealthy racist murderer Walter Wade Jr. (Christian Bale, playing a variant of his "American Psycho" character), but splinters midway through when neighborhood drug lord Peoples Hernandez ("Basquiat" star Jeffrey Wright) enters the scene. The filmmakers were so taken with Wright's compelling, over-the-top performance that they shifted everything in his direction (scenes of Roundtree and Bale were cut to give him more screen time). By the latter part of the film, the focus is entirely on Shaft versus Hernandez. Instead of the expected (and needed) mano à mano between our hero and the smug racist, the film wraps up with a lazy anticlimax.

Praise be to Isaac Hayes, who was smart enough not to "modernize" his legendary title tune. Instead of throwing in a rap segment or doing a techno treatment, he simply re-recorded the song, retaining all its funky glory. "Shaft" may only be a series of action scenes (including a few nicely done ones, by the way) held together with a tattered script and the thunder of Samuel L. Jackson, but at least that great theme remains. Hayes still croons, "They say this cat Shaft is a bad mother-- " The backup singers still cut him off with a tart, "Shut your mouth!" And when he explains, "But I'm talkin' about Shaft," I have no question which Shaft he's talking about.