Ted told me I should be able to search for this topic discussed here recently. Unfortunately I can find nothing at all.
I received an email from Google with the subject "Googlebot can't access your site http://example.com/".
Which of course is rubbish. I rarely look at webmaster Tools but for quite some time now Google has had my site under two names.
http://www.example.com/ [correct] and;
http://example.com/ [incorrect] and the thrust of the email from them.
Over the last 24 hours, Googlebot encountered 1 errors while attempting to connect to your site http://example.com/. Your site's overall connection failure rate is 50.0%. You can see more details about these errors in Webmaster Tools