Reminder to users: after uninstalling older beta, restart calibre and then install the beta 0.3, then restart calibre again.
Without the restart(s) the xpath expressions weren't correctly filled.
@kiwidude, with regards the FF import, tried it on a few authors with mixed amounts of series/individual novels etc, worked perfectly. Most impressive.

One major gripe, why couldn't you have done this last year, and saved me hours of tedious tracking down author lists
Gonna test it some more.
Many thanks.