telugunow on "[Plugin: WordPress SEO by Yoast] Unable to see post_tag-sitemap.xml"

WordPress version: 3.5
WordPress SEO version:Version 1.1.9 also tried with latest version 1.3.4.1

I did this:

I expected the plugin to do this: http://www.telugunow.com/post_tag-sitemap.xml is giving blank output

Instead it did this: http://www.telugunow.com/post_tag-sitemap.xml is giving blank output.

I tried:
i reverted back to last remember working version 1.1.9
disabled all plugins
updated latest version 1.3.4.1

i have 60K tags.

Need your help.. HAPPY NEW YEAR

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