kernel trap 19 with interrupts disabled

I have a machine which is completely locking
up solid every day or so. Its been doing this
for a couple of months on current. It is running
cvs current from ~2weeks ago.

This time, i tried shorting the NMI out, and I 
got this message to the serial console:

kernel trap 19 with interrupts disabled
NMI ... going to debugger

... but I still can't get into the debugger
with the key sequence, and no additional
output came out.

Can I assume from the 'with interrupts disabled'
that it means that all interrupts are locked off?
or that 'sti' is set? Its a MP system, a dual
xeon (P4).

suggestions?

--don