I had an almost identical question a while back...except my m.b. was an intel...and I couldn't get a a straight answer from anybody. Basically Intel told me that the voltage regulators on the mb were only rated to the highest chip speed allowed by the bios. Something about them not being able to provide the proper current (not voltage, or amperage, but current, according to them)
I don't know anything about your mb, but it's a slot 1, so you'll need a slot 2 P3 or an adapter for a FCPGA and does your board support a 133 bus?
Not to be a smartass, but you could get an athlon board and chip pretty cheap and avoid alot of headaches and possible issues with a chip that's beyond your mb specs...good luck