This may be caused by bug 57543. Could you please provide a copy of your /var/log/kern.log when this error occurs. Attach it using the web form on the bug page.
Also, can you downgrade to 2.6.17-6 and confirm that this bug disappears? Thanks. ** Changed in: linux-source-2.6.17 (Ubuntu) Assignee: (unassigned) => Simon Law Status: Unconfirmed => Needs Info -- Permission Denied on nfs clients for only some files https://launchpad.net/bugs/62308 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs