> the result that HTTrack closes without warning or error.  

Ahh.. might be an "emergency abort()" raised somewhere for 
an unknown reason ; I have added emergency logs for all 
aborts, could you test this version?In case of error ("sudden close"), a file
named "CRASH.TXT" 
should be generated, with explainations inside that will 
help me a lot to track the problem..

Please download:
<http://www.httrack.com/httrack-test.zip>
and unpack this patched winhttrack.exe file in your 
winhttrack program directory to replace the old one.