While I have no idea why, it seems that the two AppleScript workflows “Save PDF to Aperture” and “Save PDF to Folder as JPEG” are often missing from people’s systems, and these are two useful workflows when exporting Aperture-created books to other program.
I’ve posted them here for you to download. This might be against the rules, so if I get yelled at I’ll have to take them down, but since these were included in the original OS install I don’t see the harm…
download Save PDF to Aperture workflow
download Save PDF to Folder as JPEG workflow
Here is where to install them: