NFS lockd daemon doesn't register changes in /etc/resolv.conf

We have a Tru64 5.1B (latest patchkit) NFS file server which causes
problems for the NFS clients (Linux PCs).  The problem crops up when
we change the IP-address of the primary DNS server in /etc/resolv.conf
(because we have migrated our DNS service to another server).

Very strangely, as soon as we turn off our old DNS server (which is
no longer listed in Tru64's /etc/resolv.conf), a lot of NFS clients start
complaining that the "lockd" daemon on the Tru64 server is no longer
responding, and NFS comes to a grinding halt :-(  As soon as we restart
the old DNS server, the problem goes away...

Question:  Apparently the running daemons, such as rpc.lockd, do
not seem to dynamically register changes in DNS service in
/etc/resolv.conf.  Is this a bug in some DNS resolver library ?
Is there a workaround (short of rebooting the Tru64 server) ?

Thanks,
Ole

-- 
Ole Holm Nielsen
Department of Physics, Technical University of Denmark