This makes twice now that the promos for 24 have shown Kiefer Sutherland saying something about a "nucular" bomb, but when the actual episode airs, they've ADRed the proper pronunciation in.
Why do people say nucular, anyway? It's not like nuclear comprises a difficult set of phonemes. I could understand the mispronunciation of uncommon words, like unguent or phaeton, but nuclear?
Addendum: Do the people who say nucular also say likular instead of likelier?