Ex-Smashing Pumpkins bassist D'Arcy Wretzky pled guilty to possession of a controlled substance on Monday in Chicago's Cook County Criminal Court and was sentenced to spend one month in a drug education program.According to a court spokesperson, once Wretzky completes the program her case will be dismissed. If she fails to do so, the case will go back to court and she'll have to appear before a trial judge. According to the police, Wretzky was arrested on January 25 at about 2:30 a.m. after the vehicle she was riding in was pulled over for traffic violations. Police say the driver of the car was found in possession of a third of a gram of crack cocaine, which he was holding for the bassist (see "Ex-Pumpkin D'Arcy Wretzky Due In Criminal Court"). The driver's case was thrown out after his lab work turned up negative. D'Arcy and singer/guitarist Billy Corgan formed Smashing Pumpkins in 1989. The 31-year-old musician left the Pumpkins last fall, presumably to pursue an acting career. Wretzky has landed a comedic role as a killer-for-hire opposite Mickey Rourke in "Peaces Of Ronnie" (see "Former Pumpkin D'Arcy Goes Hollywood").