With ad revenue at its cable networks up 12 percent in its second quarter, Viacom on Thursday reported higher-than-expected profits of $39 million. A year ago, it reported an $83-million loss for the same quarter. Each of the media company's principal networks, including MTV, VH1, Nickelodeon and BET, reported strong earnings. The company in particular cited the huge success of MTV's Jersey Shore , which continues to draw audiences the size of broadcast network programs. Filmed entertainment from its Paramount unit also showed a huge 38-percent jump in revenue. In particular, the studio cited the strong performances of the Justin Bieber concert documentary Never Say Never and the animated Rango . However, the earnings report came just days after Jeffrey Katzenberg, whose Dreamworks Animation is a rival for Viacom's affection (Paramount currently distributes DWA features) maintained that Rango was likely a money loser when the costs of production, marketing, and revenue splits with theaters are taken into consideration.