The server was throwing a lot of errors because the search engines expect a favicon.ico file in the root of the web share. I have to draw a P5 favicon.ico but before I do that I threw a 'spare' favicon.ico into the root just to stop the error logs filling up.
Ok I have done a very quick and dirty P5 favicon file. You might have to clear your browser cache for it to take effect. It's not pretty but it makes more sense than the rather random PMA one!