The premise of this show is at least new-ish: to improvise a faux documentary in the tradition of Christopher Guest films (Waiting for Guffman, Best in Show). But the problems that bog it down are as old as improvisation: denial, dumb ideas, bad acting, poor preparation, lousy teamwork. The two women in Dirty South Improv, Erica Reid and rubber-faced Kristen Studard, know the importance of being emotionally open and setting up high-stakes relationships, especially when the characters and situations must be maintained for 45 minutes to an hour. But too many of their male colleagues still think improv's all about being silly, making funny faces, and talking in strange voices. Two minutes into the evening, desperation and self-indulgence ruled the stage. Five minutes in, the idea of parodying the documentary form had been all but abandoned. Ten minutes in, only the cast's friends were laughing. Through Sat 6/25, 10:30 PM. Then 7/2-9/17: first and third Sat of month, midnight. No show 7/16. Playground Theater, 3209 N. Halsted, 773-576-4043. $10.