Gluster users - Jun 2012 - Stale file handle?

I am getting lot of such errors in a client log:
/usr/local/var/log/glusterfs/mnt-glusterfs.log

[2012-06-05 13:39:08.513027] W
[client3_1-fops.c:2630:client3_1_lookup_cbk] 0-testvol-client-0:
remote operation failed: Stale NFS file handle. Path:
/test/api/test.sqlite3-journal (eafc297f-c600-454b-b5c7-fd973586eea8)
[2012-06-05 13:39:11.432811] W
[client3_1-fops.c:2630:client3_1_lookup_cbk] 0-testvol-client-0:
remote operation failed: Stale NFS file handle. Path:
/test/api/test.sqlite3-journal (21283629-1e10-4440-8979-f1f4c7b5efb1)
[2012-06-05 13:39:11.611532] W
[client3_1-fops.c:2630:client3_1_lookup_cbk] 0-testvol-client-0:
remote operation failed: Stale NFS file handle. Path:
/test/api/test.sqlite3-journal (1dc5dbdf-c2a5-45c7-ad69-a3e72ff4ed91)
[2012-06-05 13:39:11.681412] W
[client3_1-fops.c:2630:client3_1_lookup_cbk] 0-testvol-client-0:
remote operation failed: Stale NFS file handle. Path:
/test/api/test.sqlite3-journal (aaf137cf-25db-44f6-ae14-b582d477018c)
[2012-06-05 13:39:12.837482] W
[client3_1-fops.c:2630:client3_1_lookup_cbk] 0-testvol-client-0:
remote operation failed: Stale NFS file handle. Path:
/test/api/test.sqlite3-journal (92f30d98-1696-4d52-8c41-6e09b61a87dd)
[2012-06-05 13:39:13.206226] W
[client3_1-fops.c:2630:client3_1_lookup_cbk] 0-testvol-client-0:
remote operation failed: Stale NFS file handle. Path:
/test/api/test.sqlite3-journal (c68a52ad-a4f2-4390-9023-47c4304a9025)

Here is my server setting:

  # gluster volume info

  Volume Name: testvol
  Type: Distribute
  Volume ID: 5840405a-6b11-4371-8e89-c9bc73f45c69
  Status: Started
  Number of Bricks: 1
  Transport-type: tcp
  Bricks:
  Brick1: server1:/bricks/0001
  Options Reconfigured:
  performance.read-ahead: off
  performance.stat-prefetch: off
  performance.io-thread-count: 1
  performance.flush-behind: off
  performance.quick-read: off
  diagnostics.brick-log-level: INFO
  performance.write-behind: off

This is how I mounted the volumes:

  glusterfs --entry-timeout=0 --attribute-timeout=0
--volfile-server=server1 --volfile-id=testvol /mnt/glusterfs

What does those above warning mean? What am I doing wrong?