trouble with name resolution

I am having a problem getting "Unable to resolve hostname" errors for the
conn test for names that are in our DNS system. The bb-hosts entry looks
like:

0.0.0.0     ppd2.wcm.ess.usda.gov   # conn

the return from nslookup is:

-bash-2.05b$ nslookup ppd2.wcm.ess.usda.gov
Server:         199.128.64.2
Address:        199.128.64.2#53

Non-authoritative answer:
ppd2.wcm.ess.usda.gov   canonical name = ppd.wcm.ess.usda.gov.
Name:   ppd.wcm.ess.usda.gov
Address: 199.134.228.6

Any ideas how to correct this?

Thanks,
Larry Barber