OK, I knew it had to be simple and that a little bit of sleep would help. I forgot to update one site-specific setting after moving the app from the dev environment to production. What's ironic is the particular setting in question is part of the code I submitted to the calendar module to fix the very problem I was having. D'oh!
Poop. It seems the calendar isn't working properly on the live site, yet is working just fine on the development site. It's a bit too late (or early) for me to figure out WTF is different. Hopefully it isn't a big deal and it's just because I'm tired that it isn't obvious to me right now.
