Help w/ errors.add_to_base between controller and model


I'm having trouble in routing some errors between model and
controller. The errors produced in the controller
(invite_controller.rb) are collected and spit out nicely in a
flash[:validate] method as such:

if errors.size > 0
   flash[:validation] = errors.join('<br />')
Errors produced in the model (invite.rb) are displayed w/in a giant page
failure explosion and are not routed into the flash[:validate] method.

The code for the the method is as follows:
self.errors.add_to_base("an invitation has already been sent to
Is there a way where I can route the model errors to the
flash[:validate] method as I am in the controller?

Thanks for your help!