> > 16:51:54 Error:  "Forbidden" (403) at link www.erowid.org/ (from
primary/primary)
> 
> site might have been down at the time.
> 
> retry.  Also it contains a robots.txt, you may want
> to override that.
> 

According to the post with your log, you have the default setting for your
Browser ID:
 "Mozilla/4.5 (compatible; HTTrack 3.0x; Windows 98)"

If you can open up the site from your browser (i.e. it is not down, as Bill
suggested) and still get the error from HTT, try changing the user agent to
something else that does not have "HTTrack" in it.  They could be blocking
that.