title: Checkbox not binding to scope in angularjs
body: <p>I am trying to bind a checkbox to scope using ng-model.  The checkbox's initial state corresponds to the scope model just fine, but when I check/uncheck the checkbox, the model does not change.  Some things to note is that the template is dynamically loaded at runtime using ng-include</p>
  
  <pre><code>app.controller "OrdersController", ($scope, $http, $location, $state, $stateParams, Order) -&gt;
  
    $scope.billing_is_shipping = false
    $scope.bind_billing_to_shipping = -&gt;
      console.log $scope.billing_is_shipping
  
  
  &lt;input type="checkbox" ng-model="billing_is_shipping"/&gt;
  </code></pre>
  
  <p>When I check the box the console logs false, when I uncheck the box, the console again logs false.  I also have an order model on the scope, and if I change the checkbox's model to be order.billing_is_shipping, it works fine</p>