BEVERLY HILLS, Calif. - In a real Hollywood whodunit, 10 mailbags containing 4,000 Oscar ballots have turned up missing. The Academy of Motion Picture Arts and Sciences realized Saturday at the science and technology awards ceremony that roughly 75% of this year's ballots had not reached members. "We mailed the ballots, 4,000 of them, to Academy members last Wednesday and Price Waterhouse Coopers took the 10 mailbags to the Beverly Hills Post Office and left them there as would anybody," Academy spokesman John Pavlik said. If the ballots aren't found, the numbers on them will be invalidated and new ones will be printed and mailed tonight, according to Academy publicist Stephanie Helper. The deadline for returning ballots is March 21. The Oscars are March 26. Ballots have been lost by the post office before. In 1982, nominating ballots were mistakenly stuck into a bin marked for nonpriority bulk mail. They were found in time.