Forum Fix for Sitemaps (easy way)
 

settings > options > XML Sitemaps > Sitemap File Path .. define path with sitemaps.. example: /home/site/forums/sitemaps .... Save.. is ok

In includes/class_sitemaps.php line 757 look this:
PHP Code:
$content .= "\n\t" . '' . htmlspecialchars($this->registry->options['bburl'] . '/xmlsitemap.php?fn=' . urlencode($sitemap['loc'])) . '';

replace with
PHP Code:
$content .= "\n\t" . '' . htmlspecialchars($this->registry->options['bburl'] . '/sitemaps/' . urlencode($sitemap['loc'])) . '';

Now configure google sitemaps to view your file locate on www.yoursite.com/forums/sitemaps/vbulletin_sitemap_index.xml.gz