Most likely you see the index page from another site. This can happen wehn websites with IP and * are mixed. So either use the IP address (which you add under System > Server IP first) or * for all sites, but dont mix that.
Regarding your dns records, to verify that you dns works correctly you can use e.g.
www.intodns.com
or use the dig command:
dig @ns1.yourdomain.tld yourdomain.tld
replace ns1.yourdomain.tld with the hostname of the dns server and yourdomain.tld with your domain name.