/404.shtml does not exist. Worse things have happened, but you totally just got 404'd! You should have seen your face. It was hilarious. You were all like "I'm totally going to be going to /404.shtml," and then my server was like, "Dude, that totally doesn't exist." Now wipe off those tears and go buy yourself some ice cream.
But seriously, I'm sorry, you probably followed a bad link and it was probably my fault. If you figure out what went wrong, send me an email (firstname.lastname@example.org) and let me know about it so I can try to fix it.