NFS RPC Timed out

[Luis Fernando Llana Díaz <luis@valla.org>]

Hi all,
  I am desperated from last friday with NFS. I have two computers, sharing 
each other some directories. NFS has been working satisfactorily until last 
friday. I do not have done someting special, but since then, when I try to 
mount any remote directory I have the following messages:

root@pisarosas:~# rpcinfo -p 172.26.1.7
   program vers proto   port
    100000    2   tcp    111  portmapper
    100000    2   udp    111  portmapper
    391002    1   tcp  32768  sgi_fam
    391002    2   tcp  32768  sgi_fam
    100021    1   udp  32776  nlockmgr
    100021    3   udp  32776  nlockmgr
    100021    4   udp  32776  nlockmgr
    100021    1   tcp  32769  nlockmgr
    100021    3   tcp  32769  nlockmgr
    100021    4   tcp  32769  nlockmgr
    100024    1   udp    852  status
    100024    1   tcp    855  status
    100003    2   udp   2049  nfs
    100003    2   tcp   2049  nfs
    100005    1   udp    792  mountd
    100005    2   udp    792  mountd
    100005    1   tcp    795  mountd
    100005    2   tcp    795  mountd
root@pisarosas:~# rpcinfo -t 172.26.1.7 mountd
rpcinfo: RPC: Timed out
program 100005 version 0 is not available

Portmap is correctly configured and running, the version of the installed 
packages are:
ii  nfs-common      1.0-2woody1     NFS support files common to client and 
server
ii  nfs-kernel-serv 1.0-2woody1     Kernel NFS server support


Please need help!!!!!

Luis Llana.