I was browsing the Fighter class document in the Compendium and clicked on one of the class feature links (ASI, if I recall correctly). It took me to the marketplace page to buy the Eberron supplement. Baffling. Went back and checked. The link is to the ASI entry on the Artificer page, not to the ASI entry on the Fighter page. In fact, it looks like most of the feature links direct to the Artificer.