Mariah Carey screwed up big time -- releasing her new single BEFORE her upcoming stint on "American Idol" ... and it bombed. Did she learn nothing from Jennifer Lopez? You have to hear one caller -- who worked with Mariah on a movie -- explain how big of a nightmare she is to work with. And, Usain Bolt -- who runs short distances in a straight line -- calls himself the greatest athlete that ever lived. Charles, our resident Jamaican, is the only person who's buying what he's selling. Plus, Mark Zuckerberg loses his shirt ... and we're not talking about Facebook's plummeting stock.