NEVERMIND I"M AN IDIOT. It's a plugin conflict that I just didn't notice before going live.
I just moved my site up from a subdirectory to the main directory and now all the calendar links are broken.
They say something like this: http://www.mydomain.org/?m=20120621&cat=17
But they just redirect to the homepage.
This plugin is the only place where I am experiencing problems since the move. I've tried resetting permalinks and reinstalling the plugin. No luck.
Anyone have any ideas?