NFS - NetBSD vs OSX .. how to make them play nice ?

Hi there,

I'm sure this is NFS 101 but I'm struggling .. I've exported a  
filesystem from my Qube2 to my OSX client, but from the client side  
when I try to mount it I get "permission denied".

Here is the config :

qube2# more /etc/exports
/exports -mapall=501 -network 192.168.0/24

(I have also used "-mapall=root" to no effect, and also export to the  
clients IP rather than the whole subnet, also with no effect)

ls -al
drwxrwxrwx   2 root  wheel      512 Apr  6 09:11 exports

and this is what the Mac sees and does :

[mark-smiths-mac-mini:~] Mark% showmount -e 192.168.0.5
Exports list on 192.168.0.5:
/exports                           192.168.0.0

[mark-smiths-mac-mini:~] Mark% sudo mount 192.168.0.5:/exports /Users/ 
Mark/link
Password:
mount_nfs: /Users/Mark/link: Permission denied

ls -al
drwxrwxrwx    2 Mark  staff       68 16 Oct 15:39 link


Is there some special magic that needs to be done to make an OSX  
client mount a NetBSD export ? :-(
The OSX firewall is off, nothing else in between.


Thanks!

Mark