Comment 14 for bug 540637

Could this be related?

http://forum.linode.com/viewtopic.php?t=5549

I run into this issue and the suggested modification

1. nano +67 /etc/init.d/nfs-kernel-server
2. Comment out this line: "if [ -f /proc/kallsyms ] && ! grep -qE ' nfsd_serv ' /proc/kallsyms; then"
3. Replace with this line: "if [ -f /proc/kallsyms ] && ! grep -qE 'init_nf(sd| )' /proc/kallsyms; then"
4. Save the changes
5. NFS will now start correctly:

worked for me.