Something's Gotta Give starts as a brisk romantic comedy with an escapist Hamptons backdrop, then goes through so many location changes, narrative developments, and minutes of celluloid, it wears out its welcome. For the first and second acts, it's a delicious comedy of manners set refreshingly among older adults, with Diane Keaton and Jack Nicholson butting heads like seasoned veterans. The two film icons are in top form here, and their entertaining banter even carries over to the realm of computer instant messaging, which grounds their timeless gender battle in the present. Keaton in particular won kudos, as well as an Oscar nomination, for an utterly naked performance, both physically and emotionally. In a brave decision, the 57-year-old actress completely disrobes for a hilarious bit in which Nicholson walks in on her, nearly fracturing his neck in his haste to look away. (Never mind that any senior citizen would die to show off a body kept in such good shape.) It's the rare scene where nudity is not only germane, but key to the joke, and Keaton wins huge points for realizing that. But she loses some points by going through several long and exaggerated crying jags over Nicholson's character, which undercut the intelligent, well-realized feminist she's created. These hysterics, even played for comedy, grant Nicholson exactly the power to hurt her she wants to deny him. That may be writer/director Nancy Meyers' point, but if so, it marks the second straight film (after What Women Want) where she manages to skew her girl-power message into something more conventional and outdated.