Weird DNS problem

["Gary Hennigan" <glhenni@sandia.gov>]

I just spent a couple of hours diagnosing a DNS lookup problem, but I
have no clue what's causing the problem. If I do a

	host junker.whatever.gov

it's trying to do a lookup over the loopback interface. This times out
eventually. If I do a

	host junker.whatever.gov 134.xxx.xxx.xxx

where 134.xxx.xxx.xxx is our local DNS server everything works
fine. The request goes out over the eth0 interface and immediately
returns a valid IP for the given name.

Does anyone know why it's trying to send the request over the loopback
interface if I don't specify the IP address of a DNS server?
/etc/resolv.conf looks fine, it has a "domain whatever.gov" line and
then our two primary DNS servers. Looking at strace output of
"host junker.whatever.gov" it seems to be reading /etc/resolv.conf 

Every other network transaction works fine as long as I specify an IP
address, including routing correctly. I'm stumped!!

TIA,
Gary