> The board itself is still on-line...
> 
> Is there a way to capture all the posts of that
> existing board. No one has administrative rights. No
> one has access to the root directories.
Httrack can spider the site and capture a snapshot (assuming it not full of
fancy javascript and flash )

> the discussion software is written in Perl. We are...
The only thing you can get out of a web server is html and files, what it's
written in is irrelevant.  A mirror is not a copy it is a snapshot in time.
Forms (search, post, reply, etc.) will not function. 

> able to pull the basic scripts but HT won't go into
> the data folder (YABB2). We've tried everything and...
What does the log say, what version, what settings, what site.  Did you
disable robots.txt