i have a different brand of camcorder, but on mine video needs to be transferred using a firewire cord, not the usb. the usb is only for transferring pictures taken with the video recorder, at least on mine. apparently the firewire transfers data faster?
i ended up buying a firewire cord online and it all worked out.
the port on the recorder looks like:
and on the computer looks like:
you might check your manual, or see if there is a firewire port. i had the same kind of problems (again, diff brand) until i bought the right cable (wasnt standard with my machine).