Sorry for the delay in my response, but I did not have this model Panasonic Camcorder in house to test with. I had only the Cannon GL1 NTSC and the Sony HDR-HC1 NTSC to test with, and of course both of those worked fine through the Firewire connection.
I 'rented' the Panasonic GS-59 from Fry's Electronics.
And ran a few quick tests, and it works fine on all my machines, running Windows XP or W2K.
Can you go to your Control Panel, and Device Manager and confirm if your Firewire controller is loaded properly?