AngularJS transclude doesn't work

This example works well with AngularJS 1.1.5 (it's going to append it into div), but with 1.2.5 not (it's leaves html content without append).

https://egghead.io/lessons/angularjs-transclusion-basics

app.directive("panel", function() {
    return {
        restrict: "E",
        transclude: true,
        template: '<div class="panel" ng-transclude>This is a panel component</div>'
    }
})

AngularJS 1.1.5: http://plnkr.co/edit/BLe56D9YZxSIAiJ31wW0 ("This is..." appears as expected) AngularJS 1.2.5: http://plnkr.co/edit/h6dUrXXXBOQUtzsJqT4S ("This is..." doesn't appears)

In 1.1.5 "transclude: true" works as expected (text is appended to panel), but in > 1.2.0 not.

Any help?