ntfs-3g mounted volumes cannot be shared with nfs

hi.

i have an ntfs win xp volume i wish to share in my lan, composed by two ubuntu hardy heron machines, host, wich has win xp partitions too, and a portable computer wich has ubuntu as its OS, both machines can access internet through an adsl modem/router. they can ping each other.

for the volume i want to mount i have this info :

i have this line in fstab :

# Entry for /dev/sda8 :
UUID=01C4CDDEA0E65560 /libre ntfs-3g defaults,locale=es_ES.UTF-8 0 1

my machine mounts it at boot time, and i have this output from mount :

/dev/sda8 on /libre type fuseblk (rw,nosuid,nodev,noatime,allow_other,blksize=4096)

i can enter the volume from the machine where the disk is installed, access all the archives etc... no problems with ntfs

to be able to access the volume from my portable i have installed nfs packages

and i have this line in the exports archive :

/libre 192.168.1.0/255.255.255.0(ro)

i try to mount the /libre using nfs with this command :

mount -vvv -tnfs 192.168.1.xxx:/libre /home/root/whatever -o ro

i get this output :mount: fstab path: "/etc/fstab"
mount: lock path: "/etc/mtab~"
mount: temp path: "/etc/mtab.tmp"
mount: spec: "192.168.1.xxx:/libre"
mount: node: "/home/root/whatever"
mount: types: "nfs"
mount: opts: "ro"
mount: external mount: argv[0] = "/sbin/mount.nfs"
mount: external mount: argv[1] = "192.168.1.xxx:/libre"
mount: external mount: argv[2] = "/home/root/whatever"
mount: external mount: argv[3] = "-v"
mount: external mount: argv[4] = "-o"
mount: external mount: argv[5] = "ro"
mount.nfs: timeout set for Mon May 19 12:43:01 2008
mount.nfs: text-based options: 'addr=192.168.1.xxx'
mount.nfs: access denied by server while mounting 192.168.1.xxx:/libre

this same mount command without -o ro option does not work .

have to say that i can share ext2 volumes with the portable computer without problems. So the problem is related to the ntfs-3g and nfs interaction.

portmap running, as shows that i can share ext2 volumes using nfs.

/etc/hostname file with the name of this host computer
/etc/hosts with the ip v4 addresses dhcp usually gives to the two machines.
/etc/host.allow :
ALL: LOCAL
ALL: 192.168.1.0/255.255.255.0:ALLOW

as i stated i can share ext2 volumes so... this should be correct.

im using the adsl modem/router to connect my lan, as it has a switch of 4 ethernet ports.

This i cannot do now i have done it for years with previous versions of ubuntu and a debian machine accessing my ntfs volumes using nfs. But i then used the ntfs read only packages to access my ntfs volumes in ubuntu.

the ubuntu hardy machines are up to date in all package versions.

uname -a

Linux mymachine 2.6.24-17-generic #1 SMP Thu May 1 14:31:33 UTC 2008 i686 GNU/Linux

aptitude search commands output follows :

 aptitude search ntfs-3g
p libntfs-3g-dev - ntfs-3g filesystem in userspace (FUSE) lib
i libntfs-3g23 - ntfs-3g filesystem in userspace (FUSE) lib
i ntfs-3g - read-write NTFS driver for FUSE

 aptitude search nfs |grep ^i
i A libnfsidmap2 - An nfs idmapping library
i nfs-common - NFS support files common to client and ser
i nfs-kernel-server - support for NFS kernel server

kindly
juanito