Not "rescue" a real nail biter, in which a lot of data looked doomed!!!!!!!!!!!

I did save it, BUT, and this is important, YOU MUST FIRST CHECK AND (if required) ENABLE THE PERMISSIONS OF THE HARD DISK ON FIREWIRE (via Get Info) TO GAIN ACCESS TO IT.

I spent a few hours watching the spinning pizza of death before I realized this, as there were no messages warning me about my lack permissions.

As you say, DW couldn't fix all the errors, so I just copied the 5GB of data to the host iBook, re-installed the System on the other and then copied it back.

Yes, Firewire saved my bacon!