SooBahkDo on "[Plugin: WordPress SEO by Yoast] Sitemap Cannot Be Found"

Hello All,

This install does not work:
On one WP 3.5.1 single site installation installed in a folder clicking the XML Sitemaps button to reveal the sitemap file location produces this url and it cannot find the file.
http://www.mysite.com/blog/index.php/sitemap_index.xml

These installations work fine:
Four other WP 3.5.1 multisite installations installed as subdomain installations produce the following url:
http://mysite.com/sitemap_index.xml

Any advice about what is needed to get the single installation working properly?

Thanks,
Phil D

http://wordpress.org/extend/plugins/wordpress-seo/