BenQ Q-Video problem

The Q-Video application bundled with my new DW1640 DVD burner does not function properly when recording to a DVD+R disc from my Sony Mini DV camera.

The footage from the tape in the camera is captured via my Firewire connection kind of OK, but the window that shows the footage as it is being captured shows the captured footage in a jumpy/stop-start fashion. This is reflected in the DVD that is produced. It constantly stops and starts for very short periods, making it unwatchable. I have a 1.6 GHz Pentium P4B CPU and 512MB RAM. It seems to perhaps be a buffering problem of some sort but I’m not sure.
How can I get Q-Video to work as it is advertised to?