This document is available on the Internet at: http://urbanmainframe.com/folders/blog/20040328/folders/blog/20040328/
My apologies to anyone who's tried to post a comment on the site during the last couple of days... I'd let a little bug creep in to the CAPTCHA code which prevented a successful CAPTCHA match and, in turn, meant that no comments were accepted from non-registered users.
This glitch has now been fixed.
Kudos and thanks to Jennifer Grucza for bringing this problem to my attention.