We just rolled out a couple new comment features, and although they're pretty cool, we've been hitting a couple bugs in stuff like logging in under Firefox (anyone else have this problem?). Please be patient, and we'll hope to have all this junk fixed soon.
On another note, here's our Question of the Day for today.
Don't know how to comment? Here's how:
1) Click on the "Register" link on the top right of the page. Fill out the form by choosing a username, password and email for your eventual comment account.
2) Choose a post, click on it, and scroll to the bottom.
3) Fill in the comment.
4) Refresh the page to see if your comment shows up. If it hasn't within a day or two, try again with a better comment.