NFS server fails after upgrade to lenny

[Hendrik Boom <hendrik@topoi.pooq.com>]

I upgraded the server on my LAN to lenny recntly (after making a backup 
of the etch system (everything except user file systems)) in another 
partition.


Now when I run lennty on the server, an NFS mount from a client machine 
fails with the message (hand-transcribed from screen; there may be typos)

lovesong:~# mount /farhome
mount.nfs: mount to NFS server '172.25.1.11' failed: RPC Error: Program not registeres
lovesong:~#


But when I reboot the server to etch using the etch I saved in the backup
 partitions:

lovesong:~# #mount /ferhome
[514.141911] RPC: Registered udp transport module.
[514.143371] RPC: Registered tcp transport module.
lovesong:~#


So the upgrade seems to have damaged something.  Where should I look?

And, by the way, I have installed nfs-common.  That one seems to be
there in the etch system, too.

I'm currently running the server using my backup copy of the 
old etch system.  I'd like to be able to move to lenny, but 
right noe it's infeasible.

-- hendrik