Hi chakuza,
nice site. Downloading worked for me. I used Firefox to access the site and
when I logged in I checked the box to save the login information. After that
HTTrack downloaded fine (I also made sure all files like flv, pdf, gif, ...
were downloaded).

Also, I tried using the "capture ULR" feature. For this I can highly recommend
the Firefox add-on "SwitchProxy Tool", which makes using proxy servers really
fast and easy.

I do have a similar problem with another password protected site, that does
not allow for the password to be saved (no "remember me" option). Handling
these different kind of password protected sites surely would be a great new
feature for this already very fine software.