db/fulltext.sql might be regarded as obsolete - I dunno. Anyway I was trying to run it to confirm my text-search setup (problem was that I didn't have enough text in the test db yet). The sql is written from the point of view of creating indices, but they're all named 'ft', which won't work. So I rewrote the script to use alter table... add key, instead.
BTW, the docs should probably point to http://www.mysql.com/doc/en/Fulltext_Search.html as a resource for troubleshooting search. It explains most of the problems I've run into.