CAELinux2010 cluster - How to?

Hello,

I am starting a new post since this one got lost in a varied discussion of the previous thread...

I have made progress loading CAELinux2010.1 on two PC (ubuntu1 Quadcore and ubuntu5 single core), but I am not fully sure of the options of ASTK:

ncpus = ?
mpi_nbcpu = 4 (or 5?)
mpi_nbnoeud = 1 (2 causes a CA error)

How do I setup ASTK GUI to use both PCs?

The ~/.astkrc/mpi_hostfile (which is supposed to override defaults):
[code:1]
ubuntu1 slots=4 max-slots=4
ubuntu5 slots=1 max-slots=1
[/code:1]

The /opt/aster101/etc/codeaster/aster-mpihosts:
[code:1]
ubuntu1 slots=4
ubuntu5 slots=1
[/code:1]

The ~/.astkrc/config file is:
[code:1]
# as_run : user preferences file

# You can override here all values of $ASTER_ROOT/etc/codeaster/asrun

# remote protocol used for shell commands
remote_shell_protocol : SSH

# remote protocol used to copy files and directories
remote_copy_protocol : SCP

# editor command
editor : nedit

# login on the development server
# (name/ip address is usually set in /etc/codeaster/asrun)
devel_server_user :

#per openmpi 1.3.2
#mpi_get_procid_cmd : /home/aster/procid

#mpich2
mpirun_cmd : mpiexec -machinefile %(mpi_hostfile)s -wdir %(wrkdir)s -n %(mpi_nbcpu)s %(program)s
#mpirun_cmd : mpiexec -n 2 %(program)s

mpi_hostfile : /home/ks/.astkrc/mpi_hostfile
[/code:1]

So far I know this works:
[code:1]
mpirun -np 2 --host ubuntu1,ubuntu5 hostname
# ubuntu5
# ubuntu1
[/code:1]

Also both:
ubuntu5$: mpirun -np 4 /opt/aster101/STA10.1/asteru_mpi -c "print 'Hello World'"
ubuntu5$: mpirun --host ubuntu1 -np 4 /opt/aster101/STA10.1/asteru_mpi -c "print 'Hello World'"
works correctly, displaying 4 times 'Hello World'...

But for CodeAster ASTK, if I use: ncpus = 2; mpi_nbcpu = 5; & mpi_nbnoeud = 2 I get:
<E>_INCORRECT_PARA Requested number of MPI nodes (2) is higher than the limit (1)
<E>_INCORRECT_PARA Requested number of MPI processors (5) is higher than the limit (4)

Am I overlooking something else in the configuration process? Am I starting a cluster job incorrectly?

Regards,
JMB