Migrate error

MigrateError

$ rake db:migrate
==  CreateWarehouseTransactionStateTransitions: migrating =====================
-- create_table(:warehouse_transaction_state_transitions)
   -> 0.0641s
-- add_index(:warehouse_transaction_state_transitions, :warehouse_transaction_id)
rake aborted!
An error has occurred, this and all later migrations canceled:

Index name 'index_warehouse_transaction_state_transitions_on_warehouse_transaction_id' on table 'warehouse_transaction_state_transitions' is too long; the limit is 63 characters

Tasks: TOP => db:migrate
(See full trace by running task with --trace)

MigrateFix

#add name to index.    

add_index :warehouse_transaction_state_transitions, :warehouse_transaction_id, :name =>'audit_index'

MigratePass

$ rake db:migrate
==  CreateWarehouseTransactionStateTransitions: migrating =====================
-- create_table(:warehouse_transaction_state_transitions)
NOTICE:  CREATE TABLE will create implicit sequence "warehouse_transaction_state_transitions_id_seq" for serial column "warehouse_transaction_state_transitions.id"
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "warehouse_transaction_state_transitions_pkey" for table "warehouse_transaction_state_transitions"
   -> 0.0097s
-- add_index(:warehouse_transaction_state_transitions, :warehouse_transaction_id, {:name=>"audit_index"})
   -> 0.0107s
==  CreateWarehouseTransactionStateTransitions: migrated (0.0210s) ============

warehouse_transaction.rb

.
.
.

  state_machine :state, :initial => :incoming do
    store_audit_trail :to => 'WarehouseTransactionStateTransition'

.
.
.

warehouse_transaction_state_transition.rb

class WarehouseTransactionStateTransition < ActiveRecord::Base
  belongs_to :warehouse_transaction
  attr_accessible :created_at, :event, :from, :to
end

Does adding a name to the index break the audit trail? Doesn't seem to be logging for me.