I'm getting this exact same problem right now. I'm mirroring a site with about
4G B of html files (maybe 80,000 files or so). I'm about 1/3 of the way done
(7 hours in), and my logfile is about 2GB.


Invocation command:
httrack -%L ./List.txt -%! -A100000 -c8 -F "Mozilla/6.0 (Windows NT 6.2;
WOW64; rv:16.0.1) Gecko/20121011 Firefox/16.0.1" -O /NYRB/siteripv2 -%v

The log has about 12 serialization error lines right now, (20:18:20	Info: 
engine: warning: serialize error for
<http://www.xxxxxx.com/really_long_sentence>), repeating ever second. As the
site-rip continues, I anticipate the log size will accelerate. Should I cancel
the transfer and resume? how can I prevent this. Please advise, and I can
provide more details. Thank You!