Site Map Post Hidden

iam using SEO yoast plugin from the last week i have a issue which is my new blog posts not indexing automatically.then i checked all settings and found one issue with my sitemap.i clicked my site map and its opened but the post site map link is hidden.please help

my site : http://techcrackers.com/sitemap_index.xml

another site for reference : http://zapworld.in/sitemap_index.xml

just see the difference and help me

http://ww.wp.xz.cn/extend/plugins/wordpress-seo/