Having recently moved hosts, I've been monitoring my 404's for any pages acting funny or missing files. I've noticed something funny happening a lot in the logs. I'll get lots of 404's from nearly-legitimate pages that have the right permalink structure, but have "/none" appended to the end, so they 404.
However, it's not just happening on posts, it's also happening on categories:
Anyone seen this? Looking at the logs, there are no referring URL's to these pages, but they are still showing up. Ideas?