[Graeme]

I noticed that your site has a sitemaps.xml. It may not be valid. You can use Google Webmaster Tools to submit and/or validate your google sitemap. I suggest you check it.

You will also find that there is a newer version of the google sitemaps plugin available (3.0.3) than the current one you are using (2.7.1). 2.7.1 may not generate correct sitemap for a wordpress 2.3.2 site. Downloading the updated plugin from the plugin’s site may help.