strange error with NFS on freebsd

[Brent]

I have a 4.11 server runing nfs server and a nfs client running freebsd 5.4
ive setup both according to the freebsd handbook

http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/network-nfs.html

When i go to mount the nfs share onto the client by doing 

loqtis# mount 10.10.25.2:/user3 /user3

i get the following output
[udp] 10.10.25.2:/user3: RPCPROG_NFS: RPC: Program not registered

what does this mean ?

any help is greatly appreciated
--
Brent