Div height doesn't expand when I have a fieldset inside

[tatoboy]

I have a div that expands to the height of it's content. It works fine if I put only paragraphs () or a table inside but when I put a fieldset it doesn't expand to its height.I have used jsfiddle to make an example http://jsfiddle.net/33hgK/4/ . Anyone else had this problem? I appreciate any answers I receive.