Is it always necessary to render two separate files(video and audio) as MPEG2 before importing into DVDA ? Can't I just render as a single MPEG2 file in Vegas ?
The advantage of encoding to MPEG2 and AC3 in Vegas are that the process will NOT have to be done in DVDA and you have more control over the settings.
If you give DVDA an AVI file, create a DVD, and then decide you need to make some changes, the entire encoding process must be repeated. If you give DVDA an MPEG2 and AC3 file, the encoding has already been done.