My NS cannot lookup up this domain, help!

[John]

Hi all:

For some reason, my name server is not working with this domain
name, tekelec.com.

Here is the result of dip +trace:

---------------------------------------
ns1% /usr/local/bin/dig +trace www.tekelec.com

; <<>> DiG 9.2.2 <<>> +trace www.tekelec.com
;; global options:  printcmd
.                       270186  IN      NS      E.ROOT-SERVERS.NET.
.                       270186  IN      NS      F.ROOT-SERVERS.NET.
.                       270186  IN      NS      G.ROOT-SERVERS.NET.
.                       270186  IN      NS      H.ROOT-SERVERS.NET.
.                       270186  IN      NS      I.ROOT-SERVERS.NET.
.                       270186  IN      NS      J.ROOT-SERVERS.NET.
.                       270186  IN      NS      K.ROOT-SERVERS.NET.
.                       270186  IN      NS      L.ROOT-SERVERS.NET.
.                       270186  IN      NS      M.ROOT-SERVERS.NET.
.                       270186  IN      NS      A.ROOT-SERVERS.NET.
.                       270186  IN      NS      B.ROOT-SERVERS.NET.
.                       270186  IN      NS      C.ROOT-SERVERS.NET.
.                       270186  IN      NS      D.ROOT-SERVERS.NET.
;; Received 324 bytes from 69.28.216.5#53(69.28.216.5) in 11 ms

com.                    172800  IN      NS      A.GTLD-SERVERS.NET.
com.                    172800  IN      NS      G.GTLD-SERVERS.NET.
com.                    172800  IN      NS      H.GTLD-SERVERS.NET.
com.                    172800  IN      NS      C.GTLD-SERVERS.NET.
com.                    172800  IN      NS      I.GTLD-SERVERS.NET.
com.                    172800  IN      NS      B.GTLD-SERVERS.NET.
com.                    172800  IN      NS      D.GTLD-SERVERS.NET.
com.                    172800  IN      NS      L.GTLD-SERVERS.NET.
com.                    172800  IN      NS      F.GTLD-SERVERS.NET.
com.                    172800  IN      NS      J.GTLD-SERVERS.NET.
com.                    172800  IN      NS      K.GTLD-SERVERS.NET.
com.                    172800  IN      NS      E.GTLD-SERVERS.NET.
com.                    172800  IN      NS      M.GTLD-SERVERS.NET.
;; Received 465 bytes from 192.203.230.10#53(E.ROOT-SERVERS.NET) in 270 ms

tekelec.com.            172800  IN      NS      ns01.tekelec.com.
tekelec.com.            172800  IN      NS      ns02.tekelec.com.
tekelec.com.            172800  IN      NS      ns3.tekelec.com.
;; Received 137 bytes from 192.5.6.30#53(A.GTLD-SERVERS.NET) in 19 ms

;; connection timed out; no servers could be reached
------------------------------------------------------------

The NS can lookup up other domains fine (cnn.com, yahoo.com).
I'm just confused as how to troubleshoot this further. 

Thanks,

J.