I finally got it after working, this time with 
allowing experimentally +* and debugging mode. Don't 
know whether they have any part to this, maybe 
yesterday was just a bad day.

However, httrack does not seem to be able to explore 
further pages? Their bbs page change script is rather 
simple

<TABLE border=1 CELLSPACING=6 
CELLPADDING=0><TR><TD></TD><FORM ACTION="imgboard21-
06v.cgi" METHOD="POST">
<TD><FONT SIZE=-1><INPUT TYPE="HIDDEN" NAME="page" 
VALUE=2>
<INPUT TYPE="HIDDEN" NAME="bbsaction" 
VALUE="page_change">
<INPUT TYPE="SUBMIT" VALUE="ŽŸ‚Ì30 Œ„">
</FONT></TD></FORM>
</TR></TABLE><HR>

Doesn't httrack know how to explore forms?