Strange errors from BIND on FreeBSD 4.x system

[Brett Glass]

I'm working with a client's FreeBSD system (4.9 with patches) which 
is having trouble resolving certain domains but not others. When I 
try to execute the same queries using "dig", I see the error message

res_nsend: Protocol not supported

Via various search engines, I've seen hints that the problem may 
have something to do with IPV6 but no instructions as to how to 
resolve it. Can anyone explain what's wrong and how to fix it?

--Brett Glass