Plugin classes won't load

Hi all,

I've been working on an application which uses the smerf plugin
(Simple MEta Forms). It works fine in the development environment,
but in the production environment it seems unable to autoload anything
from the plugin directory: models, controllers, etc. I'm thinking
there must be some setting in the production environment that I need
to tweak, but don't know what. Any advice greatly appreciated. And
you can git my source here: