Multi-Threaded application unsolicited termination

Dear Trouble Shooters,

I am dispatching three processes scheduled from another
process(muti-thread) within friendly arm (mini2440) board and made to run
as a demon.

For two to three days, the process is running perfectly but after that, out
of total 4 processes, 2 processes are getting terminated.Can you tell me
the reason behind this?

With Regards.