I take the camcorder, firewire cable and test on another machine. But I couldn't find that model JVC and I didn't see what connection you tried.
not sure if this is where to put this but I have a JVC GR-D920U and i've been trying to connect it to my Powebook G4 1.67 GHz. But it just doesn't. is there anyhting i can try, or is it just not compatible at all?