I've captured (Sony TRV33) via Firewire using Movie Maker. Movie Maker recognisded the camera immediately. No problems at all.
I don't have the USB drivers installed though, so I wasn't offering Movie Maker any choice. The Movie Maker Help file offers this,
Hope that helps
Make sure your DV device is connected properly to an IEEE 1394 port, and then set the camera mode to play recorded video (often labeled VTR or VCR on a DV camera).
On the File menu, click Capture Video.
In the Movie Tasks pane, under Capture Video, click Capture from video device.
On the Video Capture Device page, in Available devices, click the DV camera.
In the Enter a file name for your captured video box, enter a file name for your captured video file. Then, in the Choose a place to save your captured video box, select the location where you want your video to be saved or click Browse to select a location.
COMPAQ something or other with 500Gb Boot Disk, 1Tb external Firewire Disk, 4Gb Memory and a super duper sound card, 19" TFT Monitor etc etc etc
Sony TRV33e : Sony TRV310e : Canon XM2
Sony Vegas Studio editions to v11
Remember, there is always more to learn than there is to teach.