> winhttrack is great and I use it a lot because I travel 
> much. I'm not an expert but have succeeded in saving a 
lot 
> of online tutorials on different topics.
> 
> However, I fail with <http://www.doom9.net>. 

Yes, because there is a frame which points to www.doom9.org 
(ORG and not NET):
frame name="thepage" src=http://www.doom9.org/

Using filters, like
+www.doom9.org/whatyouseek/*
may fit your needs