Emberjs starter-kit test fails

I have installed the Emberjs starter-kit from Github: http://ift.tt/1IZpYuP

And placed it here: http://ift.tt/1IyNr4E

And everything seems to work fine, but when I try the testing environment, by using the ?test command, it seems to fail: http://ift.tt/1IZq0TD

This all happens while I haven't made any changes to the starter-kit.

The only thing I can think of that might cause problems with the testing is the fact that fertilemedia.com has mod_rewrite (a .htaccess) at root level, but I could not find anything online about mod_rewrite interfering with the emberjs tests.

I've also tried adding:

App.Router.reopen({
  rootURL: '/playground/ember/starterkit/'
});

But this does not seem to have any effect.

Since I've made no changes to the starter-kit, and the non-test page seems to work fine, what am I doing wrong?