Hello Xavier,

I did as you suggested, creating the file hts-stop.lock 
stops the update fine.  However, when I delete the file hts-
paused.lock the update does not resume and I get the 
message "Program terminated (signal 13)" displayed.  The 
hts-in_progress.lock file is removed.  

The version of httrack is 
"HTTrack version 3.23-nossl (compiled Jun  9 2003)"

Thank you for your time.

Rick