found the problem :) had to change WebsiteUser's has_many :marks to include :foreign_key => author_id
class WebsiteUser < ActiveRecord::Base has_many :marks, :foreign_key => :author_id has_many :videos_marked, :through => :marks, :source => :markable, :source_type => "Video", :class_name => "Video" end -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk@googlegroups.com. To unsubscribe from this group, send email to rubyonrails-talk+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.