Problems with :counter_cache

I found this 'problem' (I think) when was having two self relation on the table with the same table, for instance:

Having a model like that:

create_table :codes do |t|
t.string :code_key, :null => false, :limit => 25
t.string :file_name, :null => false, :limit => 200, :default => ""
t.integer :language_id, :null => false, :default => 10
t.text :code, :null => false
t.string :comment, :limit => 250, :default => ""
t.boolean :private, :null => false, :default => false
t.integer :reply_id
t.integer :reply_id_count, :integer, :default => 0, :null => false
t.timestamps
end

In the class:

# this is a self rellation....
belongs_to :reply, :class_name => "Code", :foreign_key => "reply_id", :counter_cache => true

I'm willing to have with the self rellation the counter for that.
But a problem occours when I'm try to make an insert:

SQLite3::SQLException: no such column: codes_count: UPDATE "codes" SET "codes_count" = COALESCE("codes_count", 0) + 1 WHERE ("id" = 1)

I was surprised that the rails is trying to update a column called: 'codes_count', but I don't have a column with this name!
It is using the :class_name as a prefix of the collumn _count.

Valeu!