I have discovered a bug in the wordpress blogging software that drives this site. It results in the inclusion of a border attribute to the image tags causing the site to fail the standard of XHTML 1.1 compliance. I shall manually go through the site archives and remove the offending attributes. I can't be having a none standard compliant site can I now.
This bug has now been corrected in the software and will not result in future. Which is good news.