An alternately disturbing, humorous and ultimately life-affirming movie, "Rambling Rose" is an examination of the fall of traditional values in the Old South — some of them deserving to fall — as well as a very serious look at, of all things, nymphomania.

Surprisingly, both subjects are handled very tastefully throughout the film . . . with the exception of one scene, a moment when a 19-year-old girl climbs into bed with a 13-year-old boy and gradually allows him to explore her sexually. This scene is so explicit that it is bound to make the audience feel uncomfortable — it certainly made me squirm — and may be enough to steer you away.

Yet, that scene, early in the film, is also wildly out of sync with the rest of the movie, which is a grounded, sensitive look at a family in the changing South during the 1930s. It's an unfortunate misstep, and had that scene been eliminated, "Rambling Rose" might be on a par with "To Kill a Mockingbird" and "Tender Mercies" (both of which also feature Robert Duvall, who also co-stars here).

Still, so much here is rich and touching, not to mention the string of superb performances, that the film still merits a recommendation.

Duvall is Daddy, the head of the household, a silver-tongued charmer who runs the local hotel. His wife, Mother (Diane Ladd), a gentle, intelligent woman who is hard of hearing, is something of an early feminist. They have three children, the oldest being Buddy (Lukas Haas), who is entering puberty and, naturally, is becoming sexually curious.

The film is told from Buddy's point of view, in the form of a lengthy flashback as he recalls a particular summer in the mid-1930s when the family took in a 19-year-old girl named Rose (Laura Dern), whose troubled roots are only gradually revealed. Needless to say, this gawky young woman succeeds in turning their lives — indeed, the entire town — upside-down.

From the moment she meets the family, it's apparent that Daddy's charms have gotten to Rose, and she immediately imagines she's in love with him. At one point she even tries to seduce him, but Daddy, though he is taken with her — as is everyone in the film — doesn't allow it to happen.

From that point on Rose is stirring up the local boys, who fight over her, sneak into her bedroom and cause no end of upset in the household.

One of the most remarkable aspects of "Rambling Rose" is Dern's ability to maintain an air of innocence about all of this. What she really wants is love, of course, and she doesn't understand that sex is not the equivalent.

The film gets rather dark in places, especially toward the end when Rose thinks she's pregnant and an arrogant doctor draws a most unpleasant conclusion about how to solve her problem. In this all-important moment in the movie, Duvall takes a stand and then allows his wife to overrule him. It's a tender moment that tells us a lot about their respective levels of compassion, as well as their own relationship, and is very powerful.

Directed by Martha Coolidge with a sharp script by Calder Willingham (based on his own autobiographical novel) and a lovely score by veteran composer Elmer Bernstein, most of the film moves forward without a false note, and the acting is uniformly excellent, led by Duvall in a wonderful, natural performance. Haas, best remembered as the young Amish boy in "Witness," maintains an easy rapport with the camera, not seeming at all affected by any of the child-actor mannerisms that many young performers have. Ladd and Dern are also remarkable (they are mother and daughter in real life), and John Heard (who is in another movie opening today, "Deceived") lends nice support as the grown-up Buddy.

"Rambling Rose" is rated R for the aforementioned sexual scene. There is also some partial nudity, a few mild profanities and a bit of violence.