Try changing the extension to MPG and seeing if it works. If not, you need to mux a dummy audio track with the MPG file (even if it is silence). DVDA doesn't support elementary streams.
I have rendered mpeg2 without audio from Vega Video 4.0c using the DVD Pal template.
I renamed the m2V to mpg, and the Wav file to the same filename as the mpg video file before importing them into DVDA, but I am not sure if it is necessary, though.
My .m2v files came from CineCraftEncoders. I changed the extension to mpg, but it isn't readable by DVDA. What is the best tool for muxing without re-encoding?