"exports" errors

[Chad Leigh -- Shire.Net LLC]

My /etc/exports file looks like

/local   -maproot=0 -alldirs    localhost
/usr/ports -maproot=0 localhost
/local/2  -maproot=0 -alldirs    localhost
/local/2/jail1/usr/ports -maproot=0 -alldirs localhost
/local/jails/wo_mount -maproot=0 -alldirs    localhost 192.168.252.252
/local/2/jail1/compat -maproot=0 -alldirs localhost


Each of these entries in the exports is a separate file system.  From 
df (snipped to just show the ones in exports):

Filesystem                            1K-blocks     Used     Avail 
Capacity  Mounted on

/dev/aacd1s1d                          69418360  8911206  54953686    
14%    /local
/dev/aacd0s4d                          23787780 20364498   1520260    
93%    /local/2
/dev/da1s1c                             4056690   261000   3471156     
7%    /usr/ports
/dev/md11                               1436078   614290    706902    
46%    /local/2/jail1/compat
/dev/md10                               3045006  2281898    519508    
81%    /local/2/jail1/usr/ports
/dev/md20                               1482638   511790    852238    
38%    /local/jails/wo_mount

I don't see anything wrong with the exports file (after reading man 
exports)

But I get the following  mountd  error messages

Feb 19 01:14:37 myhost mountd[72430]: can't delete exports for 
/local/2/jail1/usr/ports: Input/output error
Feb 19 01:14:37 myhost mountd[72430]: can't change attributes for 
/local/2/jail1/usr/ports
Feb 19 01:14:37 myhost mountd[72430]: bad exports list line 
/local/2/jail1/usr/ports -maproot

over and over whenever I send a SIGHUP to mountd  (which is running  
mountd -r)

However, I can successfully mount localhost:/local/2/jail1/usr/ports  
which is shown in the following line from df:

localhost:/local/2/jail1/usr/ports   3045006  2281898    519508    81%  
   /local/jails/knd/usr/ports



Any explanation of the error (what it means and the effects)  and 
possible fixes if any would be appreciated

Thanks
Chad