I believe you have to capture with the DC-30 Mjpeg then drop it on the V-4 timeline, well anyway thats why I got rid of mine as the Mjpeg requires about a 12 meg per second hard drive to capture without dropped frames. Then I went to the DC-2000 and gave that away to my cousin and he could not fit it in his computer so it might be in the trash. Your about 5 years behind the times.
Sorry, the Vegas capture program works with 1394 devices, so you would capture the way you are used to and then open the MJPEG video in Vegas.
Many users here use a Canopus converter to capture analog with good results. Others use a camcorder such as Canon with a>d passthrough to the firewire.
Yeah, my good ole DC30 is gathering dust - it was a great card in it's time, but as musicvid says, you can capture analogue as DV via a cam or converter thru firewire.