Problem rails 3

error.log

Association named 'inventory_items' was not found; perhaps you misspelled it?

product.rb

class Product < ActiveRecord::Base

 has_many :inventory_items, :include => :size, :order => 'sizes.position ASC' , :conditions => {:deleted => false}

 scope :available_for_gallery, lambda {|*options|
    options = options.flatten.first
    conditions = sanitize_sql_for_conditions(["inventory_items.in_stock - inventory_items.processing > 0 AND inventory_items.deleted = ?", false])
    joins = :inventory_items
    if (options && options[:size].present? rescue false)
      conditions += " AND " + sanitize_sql_for_conditions( {"size_categories.name" => options[:size].split(/-/) } )
      joins = {joins => {:size => :size_categories} }
    end
    joins(joins).where(conditions)
  }


end