I agree John, as long as you search the .com (international and default US) versions of the search engines.
But in many countries, most of the people will search the local versions of the search engines. For example in France people will mainly use:
www.google.fr
fr.search.yahoo.com
search.msn.fr
And since most of the French searches won't specify the search language, pages hosted in France will be given a boost in the results.
Ok, it's no explanation to what you're seeing jameswatt. In fact I would have thought that what you're seeing would happen with a site hosted in India.