The Mac OS X “Print” menu can easily become quite a mess! Applications like Aperture, iPhoto, Yojimbo and others all automatically add convenient shortcuts to your PDF menu that make it far too clumsy to use. Of course there’s the “Edit Menu…” button at the bottom of the list to help get things back in order.
Macworld has an Mac OS X hints article including this note about PDFs and a few other good tips. You can download more automator actions direct from apple.com. While you’re getting the PDF Services menu under control, you might also check out Service Scrubber to get all the junk you don’t use out of your services menu!