"Ice Age 2: the Meltdown", the animated children's film by director Carlos Saldanha, revisits three unlikely friends of the great ice age: Manny the mammoth (voiced by Ray Romano), Diego the saber-tooth tiger (Denis Leary) and Sid the sloth (John Leguizamo). Having fled the plummeting temperatures of an impeding ice age in their last outing, they are now faced-in the sequel a scant four years later- with global warming. It's a hyper-speed reversal of fortunes. Like the kind of bad dream you'd get from too much pizza and recent exposure to an Al Gore PowerPoint slide-or a Michael Crichton debunking, depending on your political leanings-and it makes for a less then inspired plot device.

At any rate, the rising temperatures are about to cause the collapse of a huge ice dam that will flood the valley and every ambulatory life-form in the neighborhood has to make a run for it (the poor slobs in Ice Age movies are always fleeing something).

On their journey the three friends fall in with Ellie (Queen Latifah), a female mammoth who was raised as a possum, and her two adopted possum brothers Crash (Seann William Scott) and Eddie (Josh Peck). The appearance of Ellie turns Manny's world upside down. He was used to being the only Mammoth he, or anyone one he knows, had run into in a long time and was beginning to suspect he was the last of a vanishing species. Ellie brings a chance of belonging (and romance) but it is complicated by Ellie's belief that she is a possum.

With the impending flood (and the carnivorous sea creatures it will unleash) and the cross-wired romance between Manny and Ellie, "Ice Age 2: the Meltdown" has all of its plot mechanisms in place for a sentimental story of love, friendship, life lessons and the occasional flatulence joke - except for one.

Those who saw the first "Ice Age" movie will welcome the return of Scrat, the saber-tooth squirrel and his obsessive pursuit of a single acorn.

Endlessly frustrated in his quest for his prize, Scrat scurries around the periphery of the main storyline like a Sisyphus of the nut harvest and in the process we are treated to some masterful physical comedy.

The appearance of Scrat also points out an oddity of "Meltdown". This movie is a tale of two comedies.

On one hand we have the sentimentalized story of Manny's search for love with its situation comedy dialogue and careful conceits propping up its clingy insistence on charming us to the point of chuckles. And on the other, we have the primal appetites of Scrat, who learns no life lessons, makes no new friends, and demonstrates no nobility. He simply wants his acorn. Liberated from sentiment, Scrat is free to make us laugh-and he does.

What this demonstrates, in the end, is that the gods of comedy are probably Greek. Humor has more to do with the raw forces of the psyche and the tragic frustrations of our dreams than whether we learn the value of friendship. To say it another way: cute isn't funny, it's just cute.

The scriptwriters of "Meltdown" need to learn this. They spend way too much time trying to manufacture cuteness and while they're not looking Scrat steals the show. And along the way some good talent goes to waste. Ray Romano brings just the right personality Manny's curmudgeon of a mammoth and John Leguizamo does a surprising turn as Sid, giving him a voice like fingernails on a chalkboard (an appropriate quality for the annoying sidekick role). What Sid desperately needs is something funny to do besides chatter insipid dialogue.

While we may have an inclination to shrug off "Ice Age 2"'s shortcomings because its just children's entertainment, there are plenty of movies out there that have proven kids can do better. And Scrat, bless his heart, won't let us forget it.

Bruce Bulloch can be reached at wseditor@robinsonnews.com