Connecting a Panasonic SDR-H80 video camera

Hi,
I bought a Panasonic SDR-H80 video camera but can't get it connected to my iMac over USB. I turn on the camera, connect the usb-cable and selects "PC" from the camera menu, but nothing shows up on my mac to indicate any new device or drive have been added.

Anyone been successful at this or have any tips?

Thanks,
..Johan