very frustrating, I know. Does it even sto pimmediately or does it stop at a certain point in the video? Is your DV camera recognized as a device?

My problems included:
My camera not activating into DV input acceptance, I had to do it manually.
My temp storage for prerender files did not have enough space on the HD to house them (file-project settings-temp storage..even check tools-preferences and look at the storage location there) remember even though you are going to tape, you have to build avis to the HD.
Last thing I did was re-load Vegas. I have found that VV4 captures BETTER but VV3 RENDERS better so I use them for those applications.
If it stopped at a certain point in the video, I just set markers about 15 sec to the left and 15 sec to the right, rendered just that part and if it kept doing it at that same point, the problem could very well be a drop in the source file. If you think so, expand the timeline horizontally and go frame by frame with the left and right arrows frame by frame. If you get a blue screen or a black screen in the preview portion on the lower right, that is probably your problem. I was rendering 3 camera angles into one, and that took a LONG time to figure out where my trouble was..it was a few bad frames that were captured.