Are you sure that your nameservers works fine?
[root@pvclinux64 ~]# telnet 162.220.242.229 53
Trying 162.220.242.229...
telnet: connect to address 162.220.242.229: No route to host
[root@pvclinux64 ~]# telnet 162.220.242.23 53
Trying 162.220.242.23...
telnet: connect to address 162.220.242.23: No route to host
[root@pvclinux64 ~]# host ns1.sayadns.com
Host ns1.sayadns.com not found: 2(SERVFAIL)
[root@pvclinux64 ~]# host ns2.sayadns.com
Host ns2.sayadns.com not found: 2(SERVFAIL)
[root@pvclinux64 ~]# host sayadns.com
Host sayadns.com not found: 2(SERVFAIL)