Thanks, I'll do that after I have done some homework. In fact, you already given me some important point of where to look into this matter. It has something to do with SIGPIPE/ connection interrupt.

Reading thru page http://perl.apache.org/docs/1.0/guide/debug.html section "Handling the 'User pressed Stop button' case", "Detecting Aborted Connections", "The Importance of Cleanup Code" given me great deal of extra understanding of it. Thanks again.