I can still access the busicmabble back end, but annoyingly all the settings are blank so I can't check what they were.
I think the setting for spacing between threads should actually be set to 'normal' - there weren't any dividers on the old board.
The only other thing I'd change is that in Board appearance you can make the message box bigger, I had it set to:
Length of text fields: 20
Number of rows for message area: 25
Number of columns for message area: 80