I'm having a very strange issue now. When I access xml on IE, it shows updated xml files (correct google news sitemap format). But when I access from Firefox and Chrome, original (non-modified) xml shows up on browsers.
When I check via FTP, the file size is correct, and downloaded file is the correct format. But when I download via Firefox and Chrome, non-modified file shows up...
There's only one google-news-sitemap.xml on my server, so really wonder why this happens.
http://wordpress.org/extend/plugins/google-news-sitemap-generator/