I don't think that httrack can be used to get inside a
database - perhaps I misunderstood your question.  I've had
trouble with asp, too, but I only tried to get links, not go
through forms.  Sometimes I was able to get the asp links to
work better by setting the mirror deeper than necessary,
then deleting extra files; another option was to use the
scan rules  or "add urls" to add starting pages.  Sometimes
this works, other times it does not.

Cheers.