DNS lookup doesn't work, ping, firefox will not work properly
 

I have this annoying problem since day one.
I am testing out Red Hat RHEL5, everything is fine except DNS look up.
If I ping www.google.com, it doesn't work, ping ip address it all works;
if I bring up browser, put www.google.com it doesn't work, can't find the name, however, simply put ip address there it works.
My DNS seeting seems ok, and the DNS works from Windows box.

I have no idea where to look at, please help.

I have also tried dig:

dig @209.53.4.150 www.google.com ANY

; <<>> DiG 9.3.4-P1 <<>> @209.53.4.150 www.google.com ANY
; (1 server found)
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: REFUSED, id: 43439
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;www.google.com. IN ANY

;; Query time: 34 msec
;; SERVER: 209.53.4.150#53(209.53.4.150)
;; WHEN: Thu Apr 23 05:26:34 2009
;; MSG SIZE rcvd: 32

Seems to me the firewall is blocking DNS request.
Try to disable the firewall.