Annoyingly the current version of the google-news-sitemap plugin for WordPress (v1.4) doesn’t work with some silly XML namespace error reported by google.
See http://wordpress.org/support/topic/364929 and effectively the ‘patch’ on the Google Support forum thing which works fine (there are two bits of the plugin which need updating – whcih correlate to the two parts mentioned in the posting etc)
Bit annoyed that the fix is so easy – yet the plugin hasn’t been updated yet. Grr.