Shut-down when access to NFS share is gone

[Leslie Jensen]

I managed to shut down a machine with an NFS share before the connected 
client was shut down.

Now this client won't shut down. It stands at : All buffers synced.

I suspect it's waiting for the NFS server in order to disconnect.

Is there any time-out I must wait for? Will it help to bring the NFS 
server back up?

Can I in anyway tell such a client to ignore such an error?

Thanks

/Leslie