Funny or Die Presents, which premieres on HBO tomorrow at midnight, features lots of famous guest stars throughout its run, but none as excited as Karen Black, the actress known for roles in such classics as Easy Rider and Five Easy Pieces. Black posted Facebook status updates, gave interviews, and even paid for her own ad in the Hollywood Reporter all promoting her February 19 appearance on the show. The only problem? She won't be on the premiere; she's in an episode scheduled to air on April 16. "We don't know how she got confused, but she never called us to confirm the right date," an HBO employee told us yesterday. We left a message for Black's manager about the mix-up and hope she'll be able to alert her fans in time.