Okay, this isn't going so well. I've edited the About page, and now I get a 404 on it. I'm sure it worked before, and all I did was edit content. And none of the category links are working either. I started mucking with the theme code, I'm pretty knackered at the moment, and that's not the best time to start hacking with themes, but I can't see that I would have done anything bad. I'm not sure what I broke.

[Update: hmm, not even the links to posts work]