I18N error

I have the following in my en.yml

en:
  hello: "Hello world"

  activerecord:
    errors:
      models:
        et:
          not_enough: "Not enough points for this transaction"

when I call I18n.t :not_enough in my custom validation method in model
Et, I get a translation missing error. I have restarted the app, no
luck. I can translate 'hello' just fine.

Thanks