XFS/NFS incompatibility

[Imran Saeedul Haque <ihaque@xxxxxxxxxxxxxxxx>]

xfs version 2.6.25 (as reported by mkfs.xfs); kernel 2.6.11-gentoo-r4.

I am unable to mount over NFS any exported XFS file systems.  Trying to do 
so gives me:
"mount: [mount location] failed, reason given by server: Permission denied"

with [mount location] of course referring to the export. This happens over 
many different export locations.

As a test, I created a 256M loopback filesystem, and exported it, keeping 
it, the directory could be remote-mounted fine. With an XFS filesystem, I 
get the permission denied error; the mount works fine if the loopback 
contains a ReiserFS or ext2 filesystem. The filesystems are exported rw; 
I've tried using both nohide and no_subtree_check, to no avail.

Suggestions?