Don't be put off or on by the subtitle-this is one of Joel Lieber's strictly contemporary comedies of discomfort, a playfully serious projection of some of the tenebrous forces which exist anywhere. At the moment they are localized in an indeterminate small town excuding ""good healthy prejudice"" and Sidney Reuben Pfeiffer, D.D.S. is its victim. A baseless rumor that he has knocked up a young woman in his chair leads to nasty phone calls, charges that he's a political ""pinko,"" and further admonitions to settle for silence. Soon ""out of patients and out of patience."" Sidney takes off for New York and the happenings there (a street demonstration; sex; and an action-painting scene applying every foodstuff-in a grubby Village apartment) return him in a hurry to his home before the final exodus. . . . In spite of the unruly proceedings, the message comes through clearly and is catalyzed by Mr. Lieber's casually funny talent. But one suspects that he has improvised it a little too loosely and hurriedly for it to succeed quite as well as his last book Move on its own, rather special, terms.