Pings to homepage attach to top post

When other blogs link to my homepage, WP wants to attach them as pings to whatever is the current top post on the page. I’m not sure where exactly they *should* go (Movable Type doesn’t do anything with incoming homepage links), but it also seems highly arbitrary to have them attach to the top post, since the topic is likely unrelated to the topic of the pinging page.

Is this a bug or a feature? Can this behavior be disabled?