He acts, he directs, he...composes? Kevin Spacey certainly multitasked as director and star of the Bobby Darin biopic Beyond the Sea (Dec. 10); he even sings. But in a For Your Consideration Oscar ad in Oct. 27's Daily Variety, Lions Gate championed him for Best Actor and Best Original Score. Huh? Spacey's rep set the record straight: ''The film doesn't have an original score. They're all Bobby Darin songs.'' Does Spacey have to edit the ads as well?