In the page at the URL there is a blue iframe in the sidebar which contains a form with a text field, two radio buttons, a checkbox and a blue "go" button. When you move the mouse over the iframe and use the scroll wheel, it scrolls the page up, but does nothing when you scroll down (neither the iframe nor the page scroll).
Created attachment 14325 [details] Reduction
THis is probably the AppKit bug again. We really need to just work around it.
*** This bug has been marked as a duplicate of 10267 ***