Ok, it's become obvious that I installed the wrong version of slash. I've got fry (2.2.6), and I need bender (2.3).
I'm trying to make the transition as gentle as possible, since I've got the site up and running for the most part. Also, I expect upgrading will fix some of the bugs I'm having difficulties with.
I've started modifying the database so that it contains all the tables and fields in tables that it'll need for 2.3. I only have a few more changes to make there before I move on.