If the weather and the summer blockbusters have you down, take heart in Carpenter Square Theatre, a company that has come to the rescue with a fine production of Douglas Carter Beane's terrific "The Little Dog Laughed." The play is billed as a comedy, but it should not be confused with the inane, insipid comedies that frequent city stages. This is one with substance.
Mitchell (Wil Rogers) is a rising movie star whose career is shepherded by his profane buzz saw of an agent, Diane (the great Lilli Bassett). Everything is fine, except, as Diane says, Mitchell "has a slightly recurring case of homosexuality." He falls for Alex (Scotty Taylor), a New Yorker whose girlfriend, Ellen (Jennifer Wells), is a Westchester County party girl. Diane thinks it would be disastrous for Mitchell's career if word got out that he is gay, so she schemes viciously to keep the actor's secret. (This 2006 play is already becoming pass