[ILUG] Slow DNS resolution on Linux clients

[Robert Sweetnam]

Hello all,

I have a network here at home that consists of 3 Windows and 4 Linux 
machines.
The Linux machines are as follows:

1 x Ubuntu Hoary Hedgehog
1 x CentOS 4.1
2 x SuSE Enterprise 9.

Currently DNS is provided by a Windows 2000 server and the firewall/gateway 
is a Smoothwall box.
The problems that I am having are limited to the Linux machine.
When using any of them to surf the web, it takes an age before the browser 
opens it. In firefox for example there is a message in the bottom left of 
the application that says "Resolving host foo.com <http://foo.com>"
Once into a site, there is no lag when navigating to other parts of
it.Thelag appears again when attempting to access another site.
If I do an nslookup and enter a site such as linux.ie <http://linux.ie> it 
is pretty much instantaneous..

DNS configuration is the same for both the Windows and Linux machines with 
IP addresses being assigned from a DHCP server.

Any ideas?
Best Regards
Robert