So, Kevin Smith has a sentimental side. Who knew? It’s not like the New Jersey native’s past work — all of it hormonal and cunningly profane — ever tipped his hand.

From lesbian conquest fantasies ("Chasing Amy") to stoner empowerment sagas ("Jay and Silent Bob Strike Back"), playful edginess was always the motivating factor for Smith, no heart-strings attached.

Quite literally, "Jersey Girl" represents a dramatic departure for the bearded writer-director, a self-confessed comic-book dork who scraped together $30,000 and catapulted himself into cinematic cult godhood with "Clerks" in 1994. Pairing Ben Affleck with an absolutely adorable young actress named Raquel Castro, it’s an earnest, mostly non-vulgar love story about single fatherhood. Granted, Smith lays on the mawkish wuvvy-duvvy stuff a bit thick from time to time, but since he’s a novice at this game, one is inclined to give him a mulligan and let him play through.

In his most likable performance since "Good Will Hunting," Affleck ("Pearl Harbor," "Paycheck") plays Ollie Trinke, a workaholic Manhattan music publicist who meets and marries the woman of his dreams (Jennifer Lopez, more on Her Majesty later) only to suffer the worst kind of loss when she dies giving birth to their daughter, Gertie. Incapable of juggling work and parenthood, Ollie suffers a meltdown at a news conference at the Hard Rock Cafe that effectively euthanizes his career.

Fast forward seven years. Ollie has given up his swank Manhattan apartment, moved in with his father (George Carlin) in the Highlands burrough of New Jersey and is the only sanitation worker in town who drives a late-model BMW 5-series. He’s also transformed himself into a very competent father, so devoted to his child (and hung-up on his dead wife) that he hasn’t so much as been on a date in seven years.

"You gotta get back on the horse, man," a voluptuous video store clerk (ah, it is a Kevin Smith movie after all) admonishes him. Later, she offers to boost him up there herself.

The clerk, Maya, is played by milky megababe Liv Tyler (last seen as elfin princess Arwen in "The Lord of the Rings" trilogy), but Smith uses the actress mostly as a glorified condiment. Castro, as Ollie’s 7-year-old daughter, is the real female lead, and she rises sharply to the challenge, humorously portraying Gertie’s precocious qualities (her favorite play is the macabre "Sweeney Todd") without sacrificing any of her essential girliness. She also bears an uncanny resemblence to Lopez, which doesn’t hurt the overall verisimilitude.

Inevitably, "Jersey Girl" turns into one of those "Family Man"-style yuppie morality plays, wherein Ollie is offered an opportunity to get his old, fast-paced life back. Naturally, his first inclination is to grab it, but the excited, unconflicted manner in which he lusts over parties, "fashionable West Side" apartments and a nanny for Gertie seems wholly out-of-step with the moral, devoted father that Smith (who also wrote the screenplay) and Affleck have created. In other words, it feels like we’re being set up.

Smith fans, take heart — he does show a little cheek, most amusingly in the scene where Ollie tries to rent a porno movie and is playfully rebuffed by Tyler’s character. Affleck is solid throughout, but does seem to struggle in some of his many red-eyed crying scenes.

Surprisingly, Affleck’s scenes with Lopez — his former flame and cohort in the universally reviled "Gigli" — are actually pretty good, sort of like a racially reversed "I Love Lucy." Another classic case of closing the barn door when the Bennifer has already left home.