I'm having the same problem on 11th Mar 2013.
message: 

[code]
me@ubuntu:~$ httrack <http://www.world-of-lucid-dreaming.com>  -O
"/home/me/Downloads/downloads-firefox/lucid_dreaming/world-of-lucid-dreaming.com/world-of-lucid-dreaming.com" 
-%v
* Unable to create log file
/home/me/Downloads/downloads-firefox/lucid_dreaming/world-of-lucid-dreaming.com/world-of-lucid-dreaming.com/hts-log.txt
me@ubuntu:~$
[/code]

my OS:
[code]
me@ubuntu:~$ uname -a
Linux snowflake 3.2.0-37-generic #58-Ubuntu SMP Thu Jan 24 15:28:10 UTC 2013
x86_64 x86_64 x86_64 GNU/Linux
[/code]

and my httrack package:
[code]
me@ubuntu:~$ dpkg -l httrack
Desired=Unknown/Install/Remove/Purge/Hold
|
Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name                      Version                   Description
+++-=========================-=========================-==================================================================
ii  httrack                   3.44.1-4                  Copy websites to your
computer (Offline browser)
me@ubuntu:~$
[/code]
However, I found that I have problems with permissions. When I run the above
command as root or as normal user saving project into /var/tmp then the
project saves OK.