sh: 24690 Memory fault - core dumped

a customer of ours receives the following error-message:

"sh: 24690 Memory fault - core dumped"

Cycle:
In one module certain allocations are made.
After that, a second module is started with fglrun.
There, another procedure (always the same) is done.
After that, you come back to the first module.
This cycle is repeated permanently.
However, during the returning to the first module the mentioned
error-message appears eratically
(once in about 5 to 10 cycles).

A checking of the data and the sourcecode didn't bring any explanations.

Have someone heard of a similar problem?
What could be the reason?
How can this problem be solved?

I hope, that someone can help me.