nginx redirect doesn't work from any subdomain to www.site.com

hi
been asking this very same on stackoverflow, and keep getting answers that don’t seem to work with my virtualmin nginx installation
original question is
http://stackoverflow.com/questions/15266253/nginx-rewrite-all-wildcard-subdomains-to-www-site-com

Nginx doesn’t seem to recognize the
server_name *.site.com;
or the simplified one
server_name .site.com;

the code:
server {
server_name *.site.com;
return 301 http://www.site.com$request_uri;
}

server {
server_name www.site.com;
[…rest of config.]
}

doesn’t work, sends no 301 redirect but defaults to the first defined server in nginx.conf