> I've put the hts-log.txt files generated between each 
> silent exit 'crash' here:
> <http://kazemizadeh.net/httrack/wellstone.org/>

Ahah! I got a crash monitored (chance) by the debugger.. my 
god, the problem was the bogus structcheck() routine ; a 
routine I believed to be rewritten (but this was not the 
case apparently?!), as the code was quite dirty (direct 
strcat() of directory patterns to check the local 
structure.. a "temporary" routine..)
The structcheck code was randomly writing data on bad 
places, causing heap problems. 

I have wiped the function and recoded it using hashtables 
(more stable, no overflow, and no performances problems) ; 
at least the problem with this site should be fixed ; and I 
hope other problems too. This may explain most 
sudden/random crashes at end of mirrors, at least.

Darn, time to release a -6 (..)