Power down of SMP servers

[McDougall, Marshall (FSH)]

I have several Intel SMP servers that I can't get to power off
automatically.  I have googled high and low to find a process where I can
have them power off when I issue power_off or shutdown -h or any one of the
other available commands to make them do that.  Any single CPU machines I
have do it without question or any special configuration.  

These server are running RH 7.2, ES2.1 and ES3 with the various current
kernels.  Does anybody have an SMP server running Linux that will power down
when you tell it to?  If so, how did you accomplish that task. All replies
appreciated.

Regards, Marshall