> OK. Guess nobody has info... ?> 
> The problem disappeared on deleting hts-nohup.out.
> 
> I've not a clue what this file does and found only
> one ref in this forum about stopping its creation by
> making a similarly named directory instead. Haven't
> found any docs or other info on this file. Don't
> know why this file would cause the pgm to quit and
> complain about "can't somepath/hts-log.txt..."
> 
> Life is full of mystery.
> 
> Cheers, Rufus

It looks like this "is" the solution to this problem. But
don't prevent the file from being created, because it looks
like a "lock" file to prevent httrack from accepting the
SIGHUP signal. Servers usually reload their configuration
files when they are signalled with SIGHUP. Somehow httrack
did not delete this file, thus your perplexing problem.
Note that this problem may cause a mis-configuration that
would manifest itself in an unpredicatable manner,
exacerbated by subsequent human confusion and error.