It distresses me to have to report that Christopher Durang's Beyond Therapy, which was (in part) so funny off Broadway last season, comes off so leaden this year on Broadway. The explanation is not easily come by. Some of Durang's jokes were not funny then, but they were pleasantly overshadowed, or overlighted, by the ones that worked radiantly. Now, however, this play about a pair of unlikely lovers brought together by ads in the personal columns and kept apart by both their own and their therapists' hang-ups thuds with clinker after clinker: Even the lines that were riotously funny elicit only a wry smile or frozen silence.

Perhaps there is a kind of joke that does not bear repetition…. [A] good deal of Durang's humor depends on its shock value, and nothing is so shock-absorbent as a second hearing. The kind of humor that doesn't tarnish tends to...