The plugin seems to be working correctly but occasionally I get this in the error_log.
Error: PHP Warning: fopen() [function.fopen]: open_basedir restriction in effect.
File(../google-news-sitemap.xml) is not within the allowed path(s): (/var/www/vhosts/XXX/subdomains/blog/httpdocs:/tmp) in /var/www/vhosts/XXX/subdomains/blog/httpdocs/wp-content/plugins/google-news-sitemap-generator/google-news-sitemap.php on line 205
I'm guessing the current working directory is wrong - it might possibly be related to /wp-cron.php?doing_wp_cron being run
Perhaps changing line 204 from
$xmlFile = "../google-news-sitemap.xml";
$xmlFile = ABSPATH . "/google-news-sitemap.xml";
might fix it?