nfs file locking to linux nfs server

I have a feeling this has been asked, but I've been googling and haven't
found a solution.  I'm moving our home directories which are automounted
from a Tru64 UNIX server (5.1A) to a linux server (Mandriva 2006 with hand
built 2.6.16 kernel) and while the directories automount fine, running
pine on the Tru64 system hangs.  I believe the problem is that pine wants
to lock the mbox file in the home directory and the user's inbox before
transferring the new mail in the inbox into the mbox.  Some linux howtos
said for Tru64 clients one needs to add the options insecure_locks
and/or no_auth_nlm for nfs file locking.  I tried this but no success.

Any one have any ideas ?

Thanks,

Dirk