Dell Precision 530 + MPICH

[Jean-Christophe Ducom]

a)The machine is a Dell Precision Workstation530 (SMP Intel Xeon 1.7Ghz
running Redhat 7.2 kernel 2.4.17).
When the "poweroff" command is issued on the UP mode everything works
fine: the machine is turned off.
It's another story for the SMP mode (kernel smp loaded instead): all
the unmounting stuff, stopping services run smoothly but the machine
waits for me to push the power button to switch it off.
Any ideas? I already tried the apm=power-off option at the boot

b) SunGridEngine is the scheduler used on our cluster. Most of the users run
programs
using MPICH libraries. How can  I prevent users to run MPI
interactively and to bypass the scheduler? Should I write a script that checks
every jobs on the nodes and kills the 'bad' ones? Is there any MPICH 'wrapper'
for that?
Does my question make any sense?

Thank you for any information/suggestion.

        Jean-Christophe Ducom