ActiveRecord Observers and Model breakage

I'm attempting to assign ActiveRecord Observers to some of my models, specified in config/environment.rb like so,

config.active_record.observers = :presentation_observer, :asset_observer, :tag_observer

My models use plugins which extend ActiveRecord::Base, including Sebastian Kanthak's file_column

Attempting to boot mongrel yields: c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active_record/base.rb:1129:in `method_missing': undefined method `file_column' for Video:Class (NoMethodError)

This seems to indicate the plugins are not yet mixed-in when the Observers examine the ActiveRecord-descended models.

Implementing dummy stubs in config/environment.rb for these methods eliminate the errors, but don't really seem like the right way to do this.

Anyone else come up with an elegant way to get this going?