Problems with UBUNTU mounting NFS share from FreeBSD

[stan]

I've got a 4.11-STABLE FreeBSD machine that I'd like to provide NFS
services to some UBUNTU 6.10 machines. I've put the following in
/etc/exports:

/usr /usr/local/www/data/pictures  -alldirs    -maproot=0  all

When I try to mount this, I get:

root at ubuntu:~# mount black:/usr /tmp/mnt
mount: black:/usr failed, reason given by server: Permission denied

And I see the following in dmesg on the FreeBSD machine:

NFS request from unprivileged port (205.159.77.59:36731)
nfsd send error 32

I thought that I rembered having to add an option to omethng (monthd ?) to
allow it to prvide services on on privleged port, but the mountd man page
does not seem to have such an option.

How can I amke this work?

-- 
Unix is very simple, but it takes a genius to understand the simplicity.
(Dennis Ritchie)