In "Popeye," the Jekyll-and-Hyde quality of Robert Altman's filmmaking has never been more starkly evident.

On one hand, there are sequences, so deadly or wrongheaded that you feel as if you're attending his professional funeral. On the other, there are moments of transporting humorous sweetness and eccentricity.

While there are things to like in this elaborately stylized, exasperating musical slapstick fantasy -- a live-action transformation of the durable comic-strip characters created in the mid-30s by E. C. Segar -- they emerge haphazardly and flit in and out of a precarious setting. I wouldn't be surprised if children were delighted, but I wouldn't blame grownups for wanting to flee long before any of the beguiling stuff turned up on the screen.

The first 20 or 30 minutes -- in which Robin Williams as Popeye arrives in the tumbledown fishing village of Sweethaven, finds lodging in the boarding house of the Oyls and strikes up acquaintances with Shelley Duvall as Olive and Paul Dooley as Wimpy -- seemed like sheer death. I of Robin Williams' career as a movie comedian.

The dialogue was so garbled that I gave up trying to comprehend it. Some of this was a deliberate attempt to duplicate the preoccupied muttering of the cartoon Popeye and Olive, but it was still an exhausting nuisance.

After what seems like an eternity, the scene-setting and mumbling is brightened by an inventive sight gag. While confiding to Wimpy that he's searching for his long-lost father (the only discernible "plot thread" in Jules Feiffer's scenario), Popeye is ridiculed by louts eavesdropping at the local eatery. When they persist, he cleans house, boxing the head of one assailant as if it were a punching bag. This looks more like it: The action shows signs of duplicating some of the cleverness of the settings, costumes and makeup.

Still, it's only the discovery of the foundling infant Swee'Pea -- embodied by Altman's grandson, 10-month-old Wesley Ivan Hurt -- that lifts the movie out of the doldrums. He has one of those preternaturally savvy baby faces that looks simultaneously young and old. His gurgles and giggles, his range of expressions from glee to apprehension, his reactibility to the actors, give the picture a truly euphoric lift.

In the early going, Williams seems so deeply immersed in a physical and vocal impersonation of Popeye that he can't break out into spontaneous comic expression. The entrance of Swee'Pea appears to loosen and warm up his characterization.

Similarly, Williams and Duvall don't begin to establish an appealing romantic comedy rapport until the baby enters to preoccupy and unify their characters. Duvall appears an uncanny duplicate of Olive Oyl from the outset, but she outdoes herself with fluttery, goosey, endearing slapstick solicitude in the last half of the show.

Constructed by production designer Wolf Kroeger on an isolated cove on Malta, the Sweethaven sets evoke some of the ramshackle, weathered beauty of the frontier town in Altman's "McCabe & Mrs. Miller" -- but they're meant to accommodate musical comedy stylization. Altman is not adept at orchestrating stylized movement by the cast members as they traverse the steep, zig-zagging streets of Sweethaven. Moreover, that movement never evolves into sustained or satisfying dance movement.

Worst of all, composer Harry Nilson has been allowed to impose a dirge-like song score, which weighs on the production like a terminal illness. What could have possessed Altman and producer Robert Evans to inflict this unmelodic abomination on a show that needs songs with gusto and gaiety? The movie itself finally illustrates how deficient the score is by reviving Sam Lerner's wonderful, famous novelty tune "I'm Popeye the Sailor Man." The cast acts delighted, and so does the audience. Unfortunately, this highlight also happens to be the finale.

Ray Walston enters late as Pappy and promptly endears himself with a fantastic impersonation of this nutty, irritable old salt. Walston and Williams play a father-son reunion scene that evolves into a comic gem. It's also one of the few scenes which is sufficiently sustained to capitalize on Feiffer's verbal wit and affectionate familiarity with comic-strip characters. Walston gives the greatest performance of his movie career, but the movie is almost too wasteful to accommodate it.

I think it's worth tolerating Altman's blunders for the fleeting pleasures of "Popeye," but he has made it unreasonably hard on the show, the audience and his own reputation.