I have submitted Google news sitemap for my website using Xmap component of Joomla, i got the notification today as follow
Your Sitemap is on a site that is not in the Google News database. Google News can only accept Sitemaps from sites that we crawl. If your site is crawled by Google News, please check that the URL of your Sitemap agrees with the URLs of your articles as they appear on Google News, including any leading "www". If you would like to request inclusion of your site in Google News, please contact the Google News support team.
Here is my sitemap:
http://www.thepeshawar.com/index.php?option=com_xmap&view=xml&tmpl=component&news=1&id=1
Any Joomla expert can tell me, how they submit their google news sitemap or whats wrong in my sitemap.
A News Sitemap will only be accepted from sites that were reviewed by the Google News team and included in the Google News database. Since you got that warning, I believe your site is simply not in that database.
If you're publishing news content, being that breaking news or editorials, you can suggest your site for inclusion at http://support.google.com/news/publisher/bin/answer.py?hl=en&answer=40787