From CWP. /admin/index.php?module=dns_list_zones
You should have a zone ns1.(yourdomain) and ns2.(yourdomain) zones.  IF you don't you need to create them with the following
; Zone file for ns1.(yourdomain)
$TTL 14400
ns1.(yourdomain).      86400      IN      SOA      ns1.(yourdomain).      info.centos-webpanel.com.      (
      				2013071600 ;serial, todays date+todays
      				86400 ;refresh, seconds
      				7200 ;retry, seconds
      				3600000 ;expire, seconds
      				86400 ;minimum, seconds
      )
ns1.(yourdomain). 86400 IN NS ns1.(yourdomain).
ns1.(yourdomain). 86400 IN NS ns2.(yourdomain).
ns1.(yourdomain). 14400 IN A (yourip)
; Zone file for ns2.(yourdomain)
$TTL 14400
ns2.(yourdomain).      86400      IN      SOA      ns1.(yourdomain).      info.centos-webpanel.com.      (
      				2013071600 ;serial, todays date+todays
      				86400 ;refresh, seconds
      				7200 ;retry, seconds
      				3600000 ;expire, seconds
      				86400 ;minimum, seconds
      )
ns2.(yourdomain). 86400 IN NS ns1.(yourdomain).
ns2.(yourdomain). 86400 IN NS ns2.(yourdomain).
ns2.(yourdomain). 14400 IN A (yourip)