Ember is printing Hello World! twice

Ember is printing Hello World! twice

I'm just trying to get a basic ember app up and running on a rails
back-end. In application.js I have the following:
$(function(){ $(document).foundation(); });
Ew = Ember.Application.create();
router.coffee:
Ew.Router.map ->
@.resource('hi')
index.hbs:
<p>say hello{{/linkTo}}</p>
hi.hbs:
<h1>Hello!</h1>
When I load the page everything is working as it should. There's a link at
the top that says 'say hello'.
When i click the link the url at /#/hi renders, as it should. But when I
click the back button to go back to the index template and then the
forward button to go to the hi template, "Hello World!" shows up twice.
Anyone ever seen this before?