Trouble resolving one host name

Question

I'm running Lion Server with two web sites hosted on it. The two domains are resolved through DynDNS.  I can see both sites both with and without the preceding www from other machines, but when I try to access one site from a browser on the Server, itself, it cannot resolve one address if I prepend the www.  It's very odd and I cannot find anything special about that one domain name that makes it different from the other.
Here are some lookups and pings I tried from the Server itself.  The problem is if I try to get to www.chanur.net.  As you can see, the lookup for that name gives different results.
chanur:sites mark$ nslookup www.chanur.net
Server:                    127.0.0.1
Address:          127.0.0.1#53
Non-authoritative answer:
Name:          www.chanur.net.twcny.rr.com
Address: 204.232.137.207
chanur:sites mark$ nslookup chanur.net
Server:                    127.0.0.1
Address:          127.0.0.1#53
Name:          chanur.net
Address: 172.16.42.14
chanur:sites mark$ nslookup uticarocks.org
Server:                    127.0.0.1
Address:          127.0.0.1#53
Non-authoritative answer:
Name:          uticarocks.org
Address: 74.79.103.15
chanur:sites mark$ nslookup www.uticarocks.org
Server:                    127.0.0.1
Address:          127.0.0.1#53
Non-authoritative answer:
www.uticarocks.org          canonical name = uticarocks.org.
Name:          uticarocks.org
Address: 74.79.103.15
chanur:sites mark$ ping www.chanur.net
ping: cannot resolve www.chanur.net: Unknown host
chanur:sites mark$ ping chanur.net
PING chanur.net (172.16.42.14): 56 data bytes
64 bytes from 172.16.42.14: icmp_seq=0 ttl=64 time=0.040 ms
64 bytes from 172.16.42.14: icmp_seq=1 ttl=64 time=0.061 ms
^C
--- chanur.net ping statistics ---
2 packets transmitted, 2 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 0.040/0.051/0.061/0.010 ms
The name I applied to the Server itself is server.chanur.net, and configured it in the Server app for "Internet" access so I could VPN in using that name. Could that somehow be causing a conflict of some sort? 
Many thanks in advance!

Answer 1

Here's another example, where I do the nslookup from my MacBook Pro, instead of from the Server.
Node00:~ mdyson$ nslookup www.chanur.net
Server:                    8.8.8.8
Address:          8.8.8.8#53
Non-authoritative answer:
www.chanur.net          canonical name = chanur.net.
Name:          chanur.net
Address: 74.79.103.15