Viacom's first-quarter net income plummeted 36 percent to $202.9 million versus $317.2 million for the comparable quarter a year ago. The company primarily blamed heavy losses at its movie business, which it attributed to surging marketing and distribution costs. Ticket sales for its Paramount and Dreamworks releases actually rose during the quarter to $1.1 billion, helped by the success of Eddie Murphy's Norbit, a No.1 hit at the box office.