I have VCD's that I'd like to author to DVD, both PAL and NTSC.

For PAL VCD Source:
You can add it to the asset bin, but when you drag a PAL VCD source from the asset bin to a movie frame, DVD-lab crashes.

For NTSC VCD Source:
When you add them to the asset bin, DVD-Lab complains that there is a problem with the aspect ratio, but this warning can be ignored. As a side note, I've taken a look at the sequence headers of MPEG1 using DVD-Patcher, and I notice that more often than not the specified bitrate is totally wrong and the aspect ratio is not specified. DVD-Lab should take this kind of stuff into account, and also let you *set* the aspect ratio for any given movie.

Now, when you drag the NTSC source to a movie frame, the preview is just a solid green screen. This makes it impossible to add chapters.

Conclusion:
As far as I can tell, DVD-Lab is completely useless for authoring VCD sources to DVD, either PAL or NTSC.