Hi, i found recentrly this link were you can find all the drivers so you still use the dual adapter!!!
https://eww.pass.panasonic.co.jp/pro-av/support/content/download/EN/ep2main/macp2driver_e.htm
it didnt find the drivers for leopard but i downloaded and installed the drivers for tiger and tehy worked fine on mi bookpro 10.5.8
drivers for dual adapter mac
https://eww.pass.panasonic.co.jp/pro-av/support/content/download/EN/ep2main/macp2driver_e.htm