This may be a stupid quest but what is the gz for in these links to your sitemap?
Code:
# BEGIN XML-SITEMAP-PLUGIN
Sitemap: http://www.vbulletinsetup.com/sitemap.xml.gz
Sitemap: http://forum.vbulletinsetup.com/sitemap_index.xml.gz
# END XML-SITEMAP-PLUGIN
User-agent: Mediapartners-Google*
Disallow:
User-agent: *
Disallow: /pics
Disallow: /wp-admin
Disallow: /wp-login
Disallow: /wp-register
Disallow: /2006/
Disallow: /2007/
Disallow: /2008/