Make sure to connect DV camcorders via the FireWire/IEEE 1394 interface for capturing in Movie Edit Pro. That's a requirement for this procedure to work properly. USB capturing of DV camera is just not properly standardized.

If the necessary FireWire cable was not supplied with your camera, it's available at most decent computer/video stores and doesn't cost a lot of money. Same goes for the FireWire interface (e.g. as PCI plug-in card), if your computer wasn't equipped with one out-of-the-box.

If it came down to it, you could always capture with the software that was provided by the manufacturer and import the resulting DV AVI files into Movie Edit Pro, I guess. But I wouldn't really recommend it if you can make the camera work with MEP's capture function.