Thanks again for your thoughts and between the code being something I can't share here, and it being relatively complex the Short, Self-Contained, Correct Example is tricky as you suggested.

At this stage I've increased monitoring and am trying to create an environment where the problem can be reliable reproduced - if I find an answer I'll report back here.

In reply to Re^6: system >> 8 is non-zero when child exits with exit(0) by bjdean
in thread system >> 8 is non-zero when child exits with exit(0) by bjdean

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