I'm having trouble getting my ApplicationController to observe one of its values. A view is calling a function on the controller, which changes its `selectedIds` property. Another method on the controller observes this:

```
hi: function() {
  console.log('hi');
}.observes('selectedIds')

```

but only is called the first time. Is this the correct way to specify an observer?

Here's a [JSBin](http://jsbin.com/ojigev/1/edit). Open the console + click on the links, you'll see that the controller property changes but `hi` is only triggered once.