[fw-mvc] Controller class naming when using modules

Environment: ZF 1.7.0

I have a directory structure like:
/application
/modules
/default
/foo
/controllers
Foo_FooController.php

My module and controller name are the same (foo) so I wind up with a URL
like mysite.com/foo/foo/list where list is the action.

However, I'm getting an exception saying "Invalid Controller Specified
(foo)". My class name in Foo_FooController.php is FooController. I
also tried Foo_FooController and got the same error. What do I need to
name my controller class for ZF dispatcher to recognize it?

Thanks!