trap 12 with interrupts disabled, need help

[Sharad Chandra]

Hi,

	I got a message on first boot "pid <no> (<name>): trap 12 with interrupts 
disabled", then it hanged and hard boot is required.
It does not appears all the time.

I tried to figure out the problem, trap 12 is stack exception, find at the 
last
http://www.acm.uiuc.edu/sigops/roll_your_own/i386/idt.html
and is coming from kernel,
The location of this message is /usr/src/
sys/amd64/amd64/trap.c:                     "pid %ld (%s): trap %d with 
interrupts disabled\n",

What does this exception mean, and what could be possible reason that my 
program is doing wrong? How to handle it

Platform: freebsd 6.1 on amd64

--

Thanks
Sharad Chandra