Mootools referring to wrong element?

Question

Here's the logic: - Use JSONP to generate a list of articles - When the user clicks the title, do another JSONP req. and generate the content by replacing the subtitle from the previous request.

That's all nice and dandy, but this is what happens: - I click a random article title, content replaces subtitle (works great) - I click a second random title, the first content subtitle is replaced???

Here is a live demo: http://jsfiddle.net/PegsX/2/

By all logic this should work?