It's Not Me. It's Them.
Check out this MySQL bug. It's exactly what I was trying, and failing, to do this evening. Ha! For once, it's not a mistake on my part.
I'm pretty sure that the trouble I've been having with configuring my .htaccess file is all my fault though. I did manage to get it working for now, but only through the voodoo of re-typing the code. I sure hope my O'Reilly books arrive to soon to reveal the secrets.