“The Nutty Professor 2: The Klumps” is an insipid, tasteless and tactless sequel to the 1996 smash.Five years later, the visual effects are less impressive, Murphy’s caricatures are less developed, less focused, less funny and less tolerable. The idea was to center more of the movie around the entire family, so we get problems such as Sherman’s father’s impotency, or the grandmother’s horny and erratic behavior. But in the end, it ends up feeling no more like it was about the family than was the first. Their predicaments are far less notable, and their impact on you from the first (in which they were only in two scenes) tends to overpower, or outweigh their avoirdupois here. The sequel emphasizes the crude grossness far more than the first and piles on the perversion more than before, too. (I.e.: Sherman has developed a fountain of youth formula, but when his wicked alter-ego toys with it; it is administered to a hamster, and then transmutates into a giant beast and anally rapes Larry Miller. Naturally the movie doesn’t let go of this “possible” source for humor. The only funny exchange: “Mommy, look, it’s the hamster’s bitch.”) The changes tend to make the movie sag and droop, much like the grandmother’s breasts, but all the increased weight makes no correlation to an increase of laughs, because that is the only diet that has been taken here — a diet from laughs. Murphy is obviously back to the doldrums from prior to his original stint as Sherman Klump, as if that has not been completely obvious lately.