NFS export problem

[Valerio daelli]

Hello
I am trying to export two directories via NFS.
The two directories are on the same filesystem.
This is our /etc/exports file:

/raid/lower/data -maproot=root -network 10.210.0.0 <http://10.210.0.0> -mask
255.255.0.0 <http://255.255.0.0>
/raid/lower/home -maproot=nobody -network 10.210.0.0 <http://10.210.0.0>-mask
255.255.0.0 <http://255.255.0.0>
/raid/upper/db -maproot=root -network 10.210.0.0 <http://10.210.0.0> -mask
255.255.0.0 <http://255.255.0.0>
/raid/upper/scratch -maproot=root -network 10.210.0.0 <http://10.210.0.0>-mask
255.255.0.0 <http://255.255.0.0>

but we keep getting this strange errors in /var/log/messages:

Sep 29 17:38:46 biopresto mountd[411]: can't change attributes for
/raid/lower/home
Sep 29 17:38:46 biopresto mountd[411]: bad exports list line
/raid/lower/home -maproot
Sep 29 17:38:46 biopresto mountd[411]: can't change attributes for
/raid/upper/scratch
Sep 29 17:38:46 biopresto mountd[411]: bad exports list line
/raid/upper/scratch -maproot

We heard that there could be some problems sharing two directories on the
same
filesystem.
Is this true?
Thanks

Valerio