Photo by Stephen Moorer: Really, Dahling: Summer Serafin is a zany and charming Sorrel Bliss.

The effervescent comedy of manners that Noel Coward created is perhaps one of the most difficult styles of theater for contemporary American actors to play. It requires energy without mania; a light, brisk delivery without rushing or stumbling; an awareness of the comedy without ever losing the fact that these characters are deeply, mortally concerned with the feather-light burdens bedeviling them. Add to this the oh-so-very-English upper-crust dialect required in Coward''s plays and it is not surprising that few American productions are successful.

Pacific Repertory Theatre''s Hay Fever almost beats the odds. The first act, in fact, is very nearly flawless. The principal actors embrace the style as if born to it. Coward''s charm and brio are to be felt everywhere: the pace is brisk, the comedy subtle. Sadly, in the second and third acts, most of the subtlety is lost. The acting becomes shrill and forced. It is as if the director lost confidence in his audience''s ability to appreciate wit and decided that cheap humor would keep us ignoramuses chuckling.

To be fair, some audience members did chuckle. Perhaps I am being too much of a purist to cringe at, for example, the old shirt-tail-sticking-through- the- unzipped-fly gag. The spit take I could almost accept, even though it was so predictable the gentleman behind me spotted it coming two minutes before it happened.

This is by no means to say that the acting is bad. In fact, for the most part it is truly wonderful. The delicious Barbara Babcock is exquisite as Judith Bliss, the character around whom her family, the weekend and the play revolve. She acts the style to perfection. She strikes the ideal note, finding Judith''s hyper-theatricality while still allowing us to see the very real human underneath the façade. We can see exactly why her family--and assorted young men--adore her; the fact is, we do, too. In case our memories are short, Babcock''s work reminds us exactly why she has won two Emmy Awards.

Summer Serafin and Rowan Brooks both do a fine job as Judith''s children, Sorrel and Simon. Brooks'' best moments are in the opening scene when he finds the perfect blend of slovenly elegance of demeanor and witty insouciance of delivery. For the rest of the play he struggles against some rather bizarre costuming which makes him look like an escapee from a Bob Hope road movie, rather than the ultra-sophisticated bright young man Simon is. Nonetheless, Brooks triumphs over his costuming to achieve many delightful moments.

Serafin is everything the text demands her to be: beautiful, engaging, zany, charming, and unpredictable. Though at times afflicted by squeaky line delivery, she clearly understands Sorrel so well and presents her with such joie de vivre that we cannot help but like her.

Michael D. Jacobs plays the last of the four Blisses, Judith''s husband David. In his less successful moments he plays David as an English Groucho Marx. His humor becomes a bit broad and almost cries out for the signature cigar waggle. But for the most part, Jacobs adds the ideal dimension to the Bliss family. As bright, witty and extravagantly self-centered as the rest of them, he is also playful and extremely powerful. He allows us to see that the Blisses not only deserve each other, they are perfect for each other.

Julie Hughett, Steve Slack and Katie O''Bryon are very entertaining as three of the four unexpected weekend houseguests. Hughett is masterfully in command of both her character and the stage at every moment. Her sultry cattiness is a real treat. As the visiting "diplomatist," Slack is every inch the role of the terribly traditional, dyed-in-the-wool English Gentleman. O''Bryon, as the flapper brought in to be "research" for David, produces some comic gems, especially a marvelous moment when she makes a joke and cracks herself up, in spite of the lack of response from the other character on stage.

The only two disappointments in the cast are Travis Brazil as the fourth houseguest and Cindy Womack as Clara, the family''s maid. Neither evinces any sense for Coward''s style, nor for subtlety in general.

In spite of its flaws, Pac Rep''s production of Hay Fever is highly entertaining and will undoubtedly prove a very popular ticket.

Hay Fever continues at the Golden Bough through Oct. 12. 622-0100 or centerstageticketing.com.