fatal trap 12 error

[Halid Faith]

Hello

I use FreeBSD6.0.  

The machine is be locked every week.  it gives an error as below:
I add to kernel multi cpu support. Also I haven't changed the kernel 

fatal trap 12: page default while in kernel mode
cpuid=1 ; apic id = 00
fault code = supervisor write, page not present
trap number = 12
panic : page default
dumpin 1023MB (2 chunks)

That 's a strange condition that I have also another machine which has been installed Freebsd6.0.
That machine works well no problem.

How can I get rid off this condition?

Thanks