just letting you guys know what happened... So it turns out yes, you must be correct: when system() forks, for some reason the $SIG{ 'CHLD' } that I defined gets called.

I don't really need to call system(), but others who use my code do, so I decided on just overloading the system() function call with a version that uses a local $SIG{ 'CHLD' }

It works now :-)

Thanks for your help..