Lustre discuss - Oct 2011 - ll_inode_revalidate_fini() failure -43 on root directory inode

I getting this error on one client up to a couple dozen times a day...
LustreError: 17084:0:(file.c:3312:ll_inode_revalidate_fini()) failure
-43 inode 51675137
There are no corresponding errors on the OSSs, nor MDS.

I know this means there''s a race condition on the inode in question,
but my problem is that 51675137 is the Lustre filesystem''s root
directory inode.

Also, I''m assuming that "17084" is the PID of the offending
process.
If so, it is the NFS daemon.  No one has reported anything strange
going on with the filesystem, so I don''t think it''s affecting
anyone.

I tried rebooting the client, the OSSs, and running e2fsck on all OSTs
but I''m still getting the error.

Any idea why this is happening?

RHEL 5.6 and Lustre 1.8.5 (clients are NOT patchless).

Thanks!
-Joe