1) Buy Vegas Pro. This lets you "nest" multiple project files on the same timeline.
2) Start Vegas Studio twice so that it's running simultaneously in two separate windows. Open the first .vf file in one window and the second in the other window. Highlight and copy the entire second project. Paste at the end of the first project. Open the 3rd .vf file in the other window and repeat the highlight, copy, paste. Repeat again for the 4th. This method isn't great. It won't copy any track level settings or effects so it may be nearly useless.
3) Render each project separately to DV .avi files. Start a new project and load these four new .AVI files onto the timeline. Render to DVD from there.
thanks, i'll experiment with 2nd option, i've tried the third option, but it seems to lose clarity when it renders in dvd-a. can you suggest a better process? i render them in vms to avi, bring the avi's into dvd-a, they rerender and burn. i've read in some posts that saving initally to mpeg in vms allows dvd-a to avoid another render, but isn't the compression by mpeg virtually the same as a "rerendering" effect by dvd-a, kind of pick your poison scenerio?