noticing a slight delay in ping lookup

I have a DELL 2650 installed with FC5. After setting up the network I
executed some ping test to test the connections. Within the LAN the
ping replies are as expected. However, when I ping servers outside the
LAN I've noticed a slight delay in the reply of what I think is the DNS
lookup. After that the replies are as expected. Example:

linux% ping cnet.com
PING cnet.com (216.239.113.101) 56(84) bytes of data.
(*** here is where the delay is; about 2 seconds or so ***)

64 bytes from c17-sha-redirect-lb.cnet.com (216.239.113.101):
icmp_seq=1 ttl=247 time=102 ms
64 bytes from c17-sha-redirect-lb.cnet.com (216.239.113.101):
icmp_seq=2 ttl=247 time=85.7 ms
64 bytes from c17-sha-redirect-lb.cnet.com (216.239.113.101):
icmp_seq=3 ttl=247 time=93.3 ms
64 bytes from c17-sha-redirect-lb.cnet.com (216.239.113.101):
icmp_seq=4 ttl=247 time=241 ms
64 bytes from c17-sha-redirect-lb.cnet.com (216.239.113.101):
icmp_seq=5 ttl=247 time=92.6 ms

All the above replies are as expected. I can't put my figure on the
problem. I've checked my /etc/resolv.conf. It looks OK. Contains only
the COMCAST DNS IP addresses and that's it. I have another Linux
server of RH9 flavor and I don't see this problem.