The only problem is that he's never been able to shake his alter ego, Buddy Love (EDDIE MURPHY), who he accidentally created a few years back while trying to find a way to reprogram his DNA to help him lose weight. Although Sherman hasn't physically transformed into Buddy in some time, the obnoxious man hidden deep inside him is trying to cause problems, and he's generally succeeding.

To make matters worse, Sherman still finds himself embarrassed by his family -- including his grouchy father, Cletus "Papa" Klump (EDDIE MURPHY); his caring mother (EDDIE MURPHY); his libidinous Granny (EDDIE MURPHY); Ernie (EDDIE MURPHY), a cantankerous man; and nephew Ernie Jr. (JAMAL MIXON) -- and the way in which they act in front of Denise. They're tame compared to Buddy's repeated outbursts, however, so Sherman decides to rid himself once and for all of this troublemaker.

Performing an experimental genetic extraction, Sherman successfully removes Buddy. In doing so, however, he unknowingly sets into motion two serious repercussions. The first involves the fact that in altering his own genetic code, he's unknowingly created a progressively debilitating condition where his mental functioning begins to deteriorate.

Equally as bad, Buddy, through the help of a random dog hair, manages to physically manifest himself from a bottle of goo and appear once again as the fully anthropomorphic Buddy Love. As Sherman's intelligence continues to wane - much to the chagrin of Denise and Dean Richmond (LARRY MILLER), the latter who's counting on a big contract for their fountain of youth potion - Buddy then sets out to steal the formula and sell it as his own. With time running out as those situations escalate, Sherman tries to find a solution to both problems.

Beyond the stop-motion animation pioneered by Willis O'Brien, the stopping and starting of film to make people appear and disappear or change into werewolves, as well as simply drawing such effects directly on each frame of film, one of the more innovative and amazing effects (for the time) was having a performer simultaneously appear in the same scene as two different characters interacting with him or herself.

The way this was achieved before the computer age no doubt stemmed from the creation of purposeful double exposures in still photography. Filmmakers then realized that if half of a camera's lens was covered, half of the film stock would be exposed, but the other wouldn't. Thus, an actor could perform on the exposed side, the film would then be rewound and the lens covering reversed, and that performer would then act his other part on the other half of the film and then appear to play opposite themselves in the same scene.

Of course, this left a visible seam down the middle of the footage, so such scenes were near always framed along some horizontal line in the picture that would effectively mask the effect. It also meant that such scenes had to be static, with no camera movement lest the effect be ruined.

Despite those restrictions, that technique was used for decades, even appearing on TV shows such as "Bewitched." With the eventual advent of motion-control cameras and the special effects innovations created during "Who Framed Roger Rabbit," however, director Robert Zemeckis managed to shoot Michael J. Fox playing various versions of himself and other family members in "Back to the Future Part II."

The effect was amazing to behold, for not only did the various incarnations of Fox appear in the same scene, but they physically interacted with one another, all while the camera was free to move about. In 1996, Eddie Murphy and director Tom Shadyac then took that technology to new and inspired heights in their remake of the old Jerry Lewis film, "The Nutty Professor."

Although the film only contained two scenes of Murphy playing various versions of the Klump family, they were among the favorite and best-remembered moments from that picture. Since the remake went on to gross more than $250 million, a sequel was inevitable, and it now arrives in the form of "Nutty Professor II: The Klumps," a mildly amusing exercise most notable for the workhorse effort from Murphy who once again embodies the Klump clan.

In fact, that's about the only notable thing about the film. A poorly written and shabbily assembled production - courtesy of director Peter Segal ("My Fellow Americans," "Tommy Boy") and screenwriters Barry W. Blaustein & David Sheffield ("The Nutty Professor," "Boomerang") and Paul Weitz & Chris Weitz ("American Pies," "Antz") -- the movie may have a handful of decent laughs, but it comes off more as an assemblage of disparate comedic set pieces rather a fulfilling, cohesive comedy. Of course, for some viewers, part of the appeal of the original was all of the sophomoric, scatological and sex-based humor, and this sequel certainly doesn't let off on any of those elements.

Much like the original, the fart jokes are plentiful, as is attempted humor stemming from a libidinous granny and jokes coming at the expense of the obese, the aged and those with or without erectile dysfunction. Various fantasy sequences also return, and include an odd homage to the asteroid disaster films, "Armageddon" and "Deep Impact." Yet, and despite its half-hearted attempts to do so otherwise, this effort lacks the heart and charm that helped propel its predecessor, although it still suffers from some of same mean-spiritedness that permeated the first film.

I'll admit to laughing occasionally at the offerings, but that was almost always due solely to one or more of the nuances that Murphy creates in his various characters, rather than from viewing the film as a whole. In fact, Murphy's multiple performances are really the only thing that saves this film.

Playing various and distinct characters that don't look like him certainly isn't anything new for Murphy - he's done the same in films pre-dating the original "Nutty Professor" and first experimented with that back in his "Saturday Night Live Days" - but he certainly goes whole hog with it here. Although I don't know the record for playing different characters in one film, let alone one scene, Murphy certainly has to be at or near it with his effort in this film.

Playing seven characters (and two different aged versions of one of them), Murphy must be applauded simply for the massive effort, not to mention what must have been countless, grueling hours in the makeup chair (under the skillful hand of Oscar winning makeup effects guru Rick Baker who worked on the first film as well as "Men in Black" among many others) while being transformed into his various personas.

Rather than simply hamming it up in drag like Martin Lawrence did in the recent "Big Momma's House," however, Murphy creates distinct and believable - if ridiculous and absurd - characters that seem real enough that at times you can't believe Murphy's playing all of them.

Since he appears - in one form or another - in nearly every scene, however, Murphy doesn't leave much room for his co-stars to make much of an impression. As the object of one of his character's affection, pop star turned actress Janet Jackson ("Poetic Justice," TV's Fame") isn't allowed to do much other than look pretty, while Larry Miller ("Ten Things I Hate About You," "Pretty Woman") plays the same sort of character he always does.

Murphy's embodying of various characters also obviously created logistical nightmares for shooting individual scenes where the talented actor had to play against several different versions of himself. From that standpoint, the film wonderfully succeeds on a technical level, thanks in large part to visual effects supervisor Jon Farhat ("Doctor Dolittle," "The Nutty Professor") and cinematographer Dean Semler ("Dance With Wolves," "The Bone Collector").

It's just too bad that as an overall comedic experience, the film isn't funnier or better written & constructed. Although it has some funny moments - including underused but well-played bits where Buddy Love's part canine genetic code gets the better of him (an amusing moment has him being faked out by someone pretending to throw a ball) - and certainly will appease those who like their comedy best described as sophomoric and scatological, many will probably wish the film was as good and inspired as Murphy's performance(s). Unfortunately, it isn't, as thus "Nutty Professor II: The Klumps" rates as just a 4.5 out of 10.