final cut pro not recognizing camera

i have a sony vx2000 camera and recently bought a new iMac, i also got a firewire 800 cable since this is what the computer takes to hook up the camera. when i plug it in and turn the camera to playback mode and try to log and capture i get an "unable to initialize video deck" message. i used to have an older mac with a firewire 400 input and it worked just fine. am i missing something? I'm not sure if this is a final cut problem or computer issue

thanks

vincent nyguyen
macbook pro os x 10.5.8
final cut pro 7.0.3
sony nxcam hxr-nx70u