Can't Change XP 2700+ Multiplier

Hey,

I can't change the multiplier on my XP 2700+ without the system pulling a
no-POST. It's an MSI K7N2 Delta2 LSR board (nForce2 Ultra 400 chipset) with
the latest BIOS. I'm not changing any parameters other than the multiplier,
but it simply will not POST with anything other than CPU Default as the
multiplier.

Ideally, I'd like to change the CPU to something like 11x or 12x with a 200
FSB, and then do some slight upward tweaking on the FSB. Nothing major,
maybe 210 or so. I've got good DDR400 memory (1GB Crucial Ballistix), and
would like them to run at the same speeds. I've also got a solid CPU cooler
(Thermalright SLK-800) and plenty of airflow. CPU temps at stock settings
rarely hit the mid-30's.

What am I doing wrong?

Thanks,

B