I run Vegas 3.0c on a P550 w/128M RAM, 7200rpm Media Drive.
I installed a Belkin Firewire card and tried to capture video. A few minutes into the capture, it stops and gives me an error message saying the system lost communication with the DV device. Then it gives me a message saying "No combination of intermediate filters could be found to make the connection."
I figured that it just didn't like the firewire card, so I returned it and got a SIIG DV-cam Kit, one of the ones that SF says were tested with Vegas. I still had the same results.
Then I decided to try capturing video using the Ulead Video Studio Software that came with the SIIG card.
IT WORKED LIKE A CHARM!!