Are you capturing directly from the camera, or from the deck? The camera always outputs with pulldown, but the deck can output true 24P (well, PsF).
From the camera, whether you shot 24P, 30P or 60i, you'd set your capture settings to 1080i/59.94.
Also, to get native 35Mb support you'll need to update to FCP 5.1.2, which I'd highly recommend you do anyway (as soon as you're done with whatever big project you're in the middle of, of course!).
--
Jesse Rosen
Director of Technical Development
Abel Cine Tech, Inc.
