Google treats http://www.example.com/foo.html http://www.example.com/foo.html as a different page to http://example.com/foo.html http://example.com/foo.html and

Google treats http://www.example.com/foo.html http://www.example.com/foo.html as a different page to http://example.com/foo.html http://example.com/foo.html and it is completely right to do so because they could be different pages. You can use rel="canonical" to get around this, or a http redirect.