mountd: getfh failed: Operation not permitted

[Stelios Parnassidis <stel@addcom.de>]

After upgrading to portmap 5-10 / 5-11 nfs mounting of some exported 
dirs fails
while having well worked for some years now:

two machines, 1. 'nero' exports some dirs; 2. 'oren' uses the same:

machine 'nero' exports:

# /etc/exports: the access control list for filesystems which may be 
exported
#               to NFS clients.  See exports(5).
#
/               *.localnet(sync,rw,nohide)
#
/ftp            *.localnet(sync,rw,nohide)
/ftp/deb        *.localnet(sync,rw,nohide)
#  ....
/ftp/cd/dvdrw   *.localnet(sync,rw,nohide)
#  ....
#

/ftp on nero permissions:
# ll -d /ftp
dr-xr-xr-x  15 root root 4096 May 14 00:30 /ftp/

machine oren mounts:

mount nero:/ftp/cd/dvdrw
machine nero reports (syslog):
  May 14 00:23:56 nero mountd[639]: authenticated unmount request from 
oren:738 for /ftp/cd/dvdrw (/ftp/cd/dvdrw)
this is ok

then
mount nero:/ftp

machine nero reports (syslog)

  May 14 00:28:58 nero mountd[639]: authenticated mount request from 
oren:771 for /ftp (/ftp)
  May 14 00:28:58 nero mountd[639]: getfh failed: Operation not permitted

Someone seeing what is wrong?
thanks a lot