An .M2V file is usually an elementary stream MPEG-II, which DVDA currently does not support. You might be able to multiplex that into a video-only program stream using TempGENC or similar program.
I can confirm that TMPGenc will happily let you multiplex an elementary stream into a program stream with no audio using the MPEG tools provided - just do a simple multiplex and don't provide an audio file.
I do this all the time with elementary streams from CCE Basic that I want to use in DVDA.