[CentOS] NFS problem

We've been seeing what I gather is an old, traditional problem:
kernel: lockd: server <ip address> not responding, timed out

The things I've found, googling, mostly involve rebooting the NFS server,
and I can't do that, it's a home directory server for a *bunch* of people,
and this is only one person's workstation.

Are there other solutions I haven't found yet?

       mark