Enabling my second CPU

Hi,

I've bumped into a rather curious problem - not really FreeBSD specific, 
but I was still hoping some wizard could help me solve it.

I've recently changed from an Asus A7M266-D board to a MSI K7D Master-L 
board, due to the Asus dying on me. I'm running with dual Athlon 1.4ghz 
CPUs (non-MP, just plain old Athlon CPUs), and with the Asus this was no 
problem at all. Performance was fine, both CPUs were utilized well, and 
all was good.
Now with the MSI board, the BIOS complains on bootup that the CPUs I'm 
using aren't MP-capable, and that it has disabled one and is running in 
UNIprocessor mode.
As you will see in the output from mptable(1) below, the 2nd CPU is 
found, but marked as 'unusable'. Now obviously since I was using the 
same two CPUs on the Asus board, they *do* work in dual mode, and the 
chipsets on the two motherboards are exactly the same. Thus there's no 
good reason (from my POV) why the BIOS is disabling my 2nd CPU and 
ruining my fun..

Does anyone know a way to get around this? Perhaps to force-enable the 
2nd CPU in the kernel or something? I've read reports that Windows XP 
actually recognizes and uses both CPUs despite what the BIOS says, which 
to me is an indication that it should be possible somehow. I also 
suspect that the actual check in the BIOS could be disabled by some 
hackery in the BIOS flash file, however I'd like to try other options first.

If anyone think they can help, it'd be most appreciated!

With best regards,
/Eirik