When landing on a Small Web page pressing down arrow, page down or spacebar only scrolls by 5px or so. The scrollbar on the right suggests there is no more document to see.
Perhaps it uses a frameset and the content frame is not in focus. Once I click on the article the keys scroll as expected (although scrollbar height is still misleading).
I'd expect the article to be focussed and scrollable already. I don't know if this is best practice for accessibility though