I have found that sites protected with the 'amember' software can't be ripped
and mirrored using the current version of HTTrack. Reason being is that it
handles the login page in a special way. What I suggest would be that for the
proxy function that HTTrack uses to capture a url. Could it be setup to
'create' a session. Here's what I'm thinking. 

I point my browser to the proxy info that HTTrack gives me. I then navigate to
the webpage, and type in all my login info. The session is now authorized. Can
HTTrack then take that session and spider the site. Since it would be using my
session? This way people could navigate to the page they want ripped and
HTTrack could start there.