Cannot visit an authorized page.

Dear SQUID develpers and users,

  We use SQUID inside firewall machine of our company.
  I configured SQUID; single parent(proxy of firewall
  machine) as default, no sibling, passthrough_proxy for
  www server outside firewall, and local_domain & local_ip
  for www server inside firewall.

  We can visit almost of web page both inside and outside
  firwall, but cannot visit an authorized web page.
  When I visited the authorized page, a browser asked me
  username and password using a dialog. I typed both
  of that and send to server, but SQUID reply error message
  like follows.

------------------------------------------------------------
ERROR

The requested URL could not be retrieved

While trying to retrieve the URL:
http://www.newspage.com/NEWSPAGE/info/d2/d2/d1/public/B.c1209467.1mp.cmp39113.htm

The following error was encountered:

     DNS name lookup failure

The system returned:

    DNS Domain 'www.newspage.com' is invalid: Host not found (authoritative).

This means that:

    The named host probably does not exist.

Generated by squid/1.1.0@proxy.tg.omron.co.jp
------------------------------------------------------------

  SQUID seems searching URL inside firewall when it accept
  request with authorized information.

  I appreciate for any help.

Best, regards.

----
Jun Nakamura                         (e-mail: junn@zoo.ncl.omron.co.jp)
OMRON Corporation, New Business Development Division Headquaters
  C Project Group.