apt Name Resolution?

[Paul <paul@openstreet.com>]

Hi Guys: I'm having a very weird apt-get problem. I don't know that it 
is a bug. I am running Debian unstable. I run my own DNS, with two 
copies running simultaneously, one for internal and another for 
external. I am able to nslookup any domain correctly, so at least my DNS 
is working ok. I recently moved the machine to a different location and 
had to hand change the IP address in several places, one of them being 
my custom DNS set-up.

Now, when I run apt, I am getting name resolution errors and not able to 
proceed. For example: "Could not resolve...". If I use an IP address in 
my sources.list then apt works, at least for an ftp target. But, my 
machine is able to resolve the same domain name (in fact that was how i 
got the ip address).

So, I'm wondering what does apt do for name resolution that is 
different? Perhaps if I understand how it is resolving names I cna track 
down this problem. I'm guessing it is not a problem with apt?

Thanks for any ideas,
--Paul

p.s. I have my domain heavily spam protected. e-mails from debian.org 
are ok, but anything else might bounce.