imovie freezes when camera turns on

every time I turn on my JVC video camera (GR-D250), my imovie immediately freezes up and won't even force quit--I have to turn off the computer by holding down the power button. I got about 10 seconds of footage imported the first time I tried before it froze, and it hasn't let me get that far again since. I have the camcorder plugged into an external hardrive's firewire port, since when I plug it into the regular port imovie won't recognize it, and it's in playback mode and everything--what's going on? gahh!!