Models and Modules and subclassing, oh my!

So, our application has a large number of models at this point, and I'm getting a bit worried about people having to use long names, as well as clashes in the global namespace. More recently I wanted to add a new table with some STI subclasses of that table...

module Portal end

class Portal::Base < ActiveRecord::Base     belongs_to :widget end

However, Widget is a top level class, Object::Widget. What I find is that this generates an error, Portal::Widget (portal/widget.rb) could not be found. Is this a problem with the way ruby or rails is attempting to load this class under the module? I suppose that it is ambiguous, did I mean Portal::Widget or Object::Widget, but the ambiguity should be able to be resolved by the fact that Portal::Widget doesn't exist, but Object::Widget does.

Has anyone dealt with this before?