Fatal Trap 12 on SMP

[Susan]

MY equipment is a Tyan 2460 dual CPU with 760 of ram. I am running 
FreeBSD 5.1 Release without the SMP compilied into the kernel.When I 
build and install kernel with the SMP components the new kernel will not 
load. I get the Fatal Trap 12 error. I have compiled the SMP components 
on FreeBSD 5.0 Release and so I don't suspect a hardware problem as 
sugested on the FreeBSD forams. Thanks Phil