What if you make a music compilation? You can add video files there too. Just go to File - New - Music Compilation, add the files as desired, and burn. (you may want to delete the automatic "titles" on each file.
But then again - by definition - that wouldn't be a SINGLE menu less movie in DVDA....it would be a music compilation showing video. Which would defeat the purpose of trying to add multiple movies in a SINGLE menuless DVD.
You could do a DVD with "continuous video(s)". The easiest of which is to slam all the videos together in Vegas and just make one big file out of them...then bring it into DVDA as one file.
Currently end actions aren't supported directly in DVDA (that is....start video 2 after video 1 starts....start video 3 after video 2 starts....and so on).
There is a great walk through on how to use Infoedit to get around this. I forget the thread it is in...do a search - it should come up.
Other than that....the music compilation is a good idea too.
But I'm going to work on getting 3 or 4 movies in the single movie mode. That sounds challaging to me.