I added a new DNS Zone record for your domain. This change may take a little while to be fully effective. Could you give it some time then try updating the name servers again? You will need to update the name servers as below:
NS1.WORDPRESS.COM
NS2.WORDPRESS.COM
NS3.WORDPRESS.COM
For more information, please visit the help documentation provided by the registrar and our support page:
http://en.support.wordpress.com/domain-mapping/map-existing-domain/