I found this forum entry (see post 13) , and essentially I needed to install bison and flex. I issued this command to make sure I had everything:
yum install make bison flex gcc
I think it was 'bison' that made the difference, because I've actually seen a different error when flex is not installed.
I have to say, Till and Falko (and others?) at HowToForge are fantastic, and have created a great resource on the web. These guys really know their stuff and are very helpful.