Apparently some comments are not appearing on the site, even though I can see them in the Blogger admin system. This seems to be a problem with Disqus not picking up comments made via the mobile version of the site. I'm trying to fix it at the moment. I think this only affects one comment so far, and it hasn't been lost.
Also, some readers have said they can't leave anonymous comments on the site. You should be able to - just post as a 'Guest' and enter a made-up email address.