Second keymap bug. Currently, some items in the keymap editor have dynamic names relating to the tool in use. By that, I mean that if you haven't done anything in your current document, you'll find "Undo" under Edit. However, if you've just performed a Fill, the keymap editor will now read "Undo Fill". The keymap for "Fade" exhibits the same behavior. It was a little confusing to figure out, and I don't think that's the intended functionality.
Cheers