Ember.js: Custom Slug URLs not working after refresh

I'm trying to setup custom slug URLs for my page models in Ember. They're working so far when I call the links from the index page. What's not working however, is that if I refresh the page with one of my custom URLs, the model is not found anymore and I'm being redirected to my "not found" page. So maybe it's a "timing" problem and I should load the models in a different way?

I followed the tutorial in the Ember guides and checked this question on StackOverflow but I still cannot get it to work.

Here's my source code snippet so far: http://ift.tt/1G50TN9

Thank you very much in advance - every help/comment is appreciated.